When logging in through the non-Mikrotik wireless extender (WAVLINK AC1200):

/ip active users > show multiple devices using same extender MAC with different IP address for each, without asking for login after first (any) device (using same password!).

/ip dhcp-server lease > show correct client MAC for each device.

How can I make hotspot use the correct client MAC from the dhcp-server for login, e.g. bypass the extender MAC?

Below is my setup - indicating what I have tried, kindly help:

ip pool (hs-pool-8):
Addresses: 192.168.4.2-192.168.4.254

hotspot server settings:
Address-pool: none (tried changing to 'hs-pool-8' along with same in Profile setting, not working)

dhcp-server settings:
address-pool: hs-pool-8
Add ARP for Leases [Checked] (tried check and uncheck, along with Bridge ARP, not working)
Use Radius: No

Bridge settings:
ARP: Enabled (tried checking and unchecking as mentioned in dhcp-server settings above, not working)

hotpsot ip-binding settings:
bypass, mac-address of extender (connects anyone even without login, only lease shows without even appearing in active users, not working)
bypass, ip-address of extender (nothing happens, not working)
block, mac-address of extender (no login or internet at all, not working)

Thank you

A very well known problem with extenders (repeaters).
There are different modes. Most extenders are set in "Universal mode". This is a level 2.5 bridge, replacing the original MAC of the client with its own MAC address, and keeping track of the original IP address, to be able to redirect the answer.
(This is also the Mikrotik "pseudo bridge" mode as far as I understand).

The DHCP was able to give a unique IP address because the MAC address is not taken from the data packet headers but from the data in the packet.
Later communication does not have that client MAC address included (except for WDS or Mkt Bridge mode).
Any control based on MAC address will treat all clients behind the extender as one and the same device, as only the MAC address of the extender is received.

There are other extender modes besides "Universal" and "WDS". The "Proxy" mode.
https://www.tp-link.com/nl-be/support/faq/927/

Unfortunately I have a RE450. So only Universal mode is possible, and all clients connected to the Range Extender are treated equal.
Unless I could filter on IP address of the clients, not on the MAC address. (Did not try this with Mikrotik. Didn't work with Fortigate nor Draytek.)
And no, the ARP table is of no help, all clients will have the same MAC address there.

Agree totally with @bpwl and also add the only method to bridge transparently is with wds that is compatible with different vebndors if the device supports it. Other methods usually fall into compatibility issues. These devices will use the same chip to recieve and transmit data to the client and will affect much performance. Rather than some noise from the other room you will not get any benefit from it in my experience. The only reliable method to use these devices is to bridge them by an ethernet cable and put the extender in ap mode in a different channel from the main ap.

I have a WAVLINK AC1200 (WL-WN579X3) that works perfectly in Bridge mode.
(Bridge mode is suppose to disable extender DHCP IPs so they can be handled by Mikrotik).
https://www.wavlink.com/en_us/product/WL-WN579X3.html

In question is WAVLINK AC1200 (WL-WN575A3) with exact settings in Bridge mode doesn't work, this is the one mentioned in this post.
https://www.wavlink.com/en_us/product/WL-WN575A3.html

device dhcp-server lease MAC is correct, however hotspot active user MAC is not correct.

Active users MAC cannot be changed manually using on-login script.

Any way to have to force Mikrotik to register the device MAC instead of the extender MAC on login?

I have a WAVLINK AC1200 (WL-WN579X3) that works perfectly in Bridge mode.
(Bridge mode is suppose to disable extender DHCP IPs so they can be handled by Mikrotik).
https://www.wavlink.com/en_us/product/WL-WN579X3.html

In question is WAVLINK AC1200 (WL-WN575A3) with exact settings in Bridge mode doesn't work, this is the one mentioned in this post.
https://www.wavlink.com/en_us/product/WL-WN575A3.html

device dhcp-server lease MAC is correct, however hotspot active user MAC is not correct.

Active users MAC cannot be changed manually using on-login script.

Any way to have to force Mikrotik to register the device MAC instead of the extender MAC on login?

I don't see any functional difference between those devices. The "marketing" language is not the most adequate way to describe these precise technical differences.
Bridge mode? I only see Router/Repeater/AP mode. I suppose it is used in "Repeater" mode. The AP mode should be perfect (no MAC substitution)

If you cannot filter on IP address, then the only alternative I see now is using some kind of tunnel or VPN. E.G. PPPoE from the client. (No hope this tunnel can be done on these devices)
The other option is to find a compatible "WDS" AP to replace the WavLink (A Mikrotik will do , but you will loose the beamforming )

Repeater mode can be set to AP or Bridge:
1 - AP (DHCP is on but can be disabled manually, not sure why one would disable DHCP)
2 - Bridge (I suspect this disables DHCP and similar to WDS only MAC is visible, that is why I see all devices with the same MAC - no specific WDS options is available in admin)

UPDATE:

Login solved: It actually works in Bridge mode and each person is asked for a password, but logged-in users get assigned same MAC! (WDS maybe?)

Login problem occurs, steps:
1 - login via wireless extender in Bridge repeater mode (lease has correct MAC, hotspot active user has extender MAC)
2 - login via a wired second router in Bridge - failed (lease has device MAC)
3 - removed lease and retry login - success (lease and hotspot user have same MAC)
4 - login via wireless extender in Bridge repeater mode - failed (lease has device MAC)
5 - removed lease and retry login - failed (even removed all leases and tried to remove APR, still failed)
* wired second router is connected directly to Mikrotik and distributes wifi.

Removing lease fixes login via wired second router, but I cannot do the same by removing lease to login again via the wireless extender, the lease MAC is the same!

Only Reboot fixes login via wireless extender again, any attempt to login via wired second router causes this.

Any idea why I need to remove lease to allow login via wired second router, and why it doesn't work for extender?

[SOLVED]

Wavlink was problematic, in Bridge Mode it works fine but it keeps disconnecting and reconnecting the device every few minutes in random interval.

Solution: tp-link TL-WA850RE in Extender Mode (I think previously called Proxy Mode)

tp-link TL-WA850RE for $22, changed its gateway to the Mikrotik router, it was already in 'Extender Mode' (there are two modes, Extender and Access Point Mode).
* make sure you set the gateway to Mikrotik main IP, otherwise the connected device will not show in dhcp-server lease list and only shows in ARP.

Works flawlessly, and cheap.

Alternative was Unify AC Lite $87 that I read compatible with Mikrotik if you disable captive portal and enable guest.