Hello everyone
Today suddenly without any change in my routers configurations all of them (v6.48.3 and v6.48.4 and v6.48.4) got "DoH server connection error: SSL: handshake timed out (6)" in log, all starting at the same time and DNS stopped working which was working fine for few month.
I tried all the method and examples in this topic viewtopic.php?t=160243 as well but still not getting any resolve on any of the devices. also getting "DoH server connection error: resolving error" in the log after changing some settings. or I can open the websites but it's very slow and there is a lot of timeouts.
My settings are (I have DigiCertGlobalRootCA.crt.pem_0 and with this it was working fine but today after that error and searching for a solutions as it was suggested by normis I add all the https://curl.se/ca/cacert.pem certificates but still same problem) : Also tried this settings viewtopic.php?t=160243#p787643 but still got the same "DoH server connection error: SSL: handshake timed out (6)" error.

Is it a problem with mikrotik? should I contact mikrotik support?

I just sent a ticket to support.

Well, this is their final anwser

I'm having the same issue
Lots of entries in the log

19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:15:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:16:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error
19:17:48 dns,error DoH server connection error: resolving error

DNS seems to work, and there are cached entries, but not sure what this error relates too. Every now and then I get a failed page load and a refresh solved that so I do think there is an issue

/ip/dns> print
servers:
dynamic-servers:
use-doh-server: https://security.cloudflare-dns.com/dns-query
verify-doh-cert: yes
allow-remote-requests: yes
max-udp-packet-size: 4096
query-server-timeout: 2s
query-total-timeout: 10s
max-concurrent-queries: 500
max-concurrent-tcp-sessions: 200
cache-size: 5120KiB
cache-max-ttl: 1w
cache-used: 242KiB

/ip/dns/cache> print where name~"*cloudflare*"
Flags: S - STATIC
Columns: NAME, TYPE, DATA, TTL
# NAME TYPE DATA TTL
13 S cloudflare-dns.com A 104.16.248.249 0s
14 S cloudflare-dns.com A 104.16.249.249 0s
19 S security.cloudflare-dns.com A 1.0.0.2 0s
20 S security.cloudflare-dns.com A 1.1.1.2 0s

Hi,
I had the same problem. I am using an RB 4011 with ROS V6.49.6.
Please try "https://1.1.1.1/dns-query" as the cloudflare DOH dns request and disable your static DNS entries for cloudflare. It should now work with the 1.1.1.1 IP as well, since the cloudflare certificate allows it.
So you can use "verify DOH Certificate" with the cloudflare certificate installed.
Also do not use dynamic or other DNS servers.
With these settings I no longer have problems with DOH.
No more error messages from DOH.
But that also means that there is a bug in connection with static DNS entries and DOH.

Regards,
Thomas

Well, this is their final anwser
Screenshot 2021-11-08 140020.jpg

That is pathetic!

Hello I have the same problem here on this topic no one answered to the 2nd problem which is the almost same problem as yours have figured it out ?

viewtopic.php?t=191624