I have a hEX S router and RouterOs v 7.13 beta 4 installed on it. I would like to point out that in the previous software version 7.13 beta 3 this problem also occurs, namely the running Wireguard server generates a terrible number of logs.
I guess it's because of the fix *) wireguard - optimized and improved WireGuard service logging that appeared in version 7.13 beta 3.
I haven't noticed this problem on previous versions.

For now there is a easy fix

Thank you, i've noticed this as now it's on the stable release.

is-responder (yes | no; Default: no)

Specifies if peer is intended to be connection initiator or only responder. Should be used on WireGuard devices that are used as "servers" for other devices as clients to connect to. Otherwise router will all repeatedly try to connect "endpoint-address" or "current-endpoint-address" causing unnecessary system logs to be written.

Can you specify where "is-responder" should be located? Because on Winbox app (android) there is no such option for any WG or peer in menu. Also non of them were created by QR code, they were created manually before 7.14.3 update.
I have WG flood in log, this must be stopped.

is-responder (yes | no; Default: no)

Specifies if peer is intended to be connection initiator or only responder. Should be used on WireGuard devices that are used as "servers" for other devices as clients to connect to. Otherwise router will all repeatedly try to connect "endpoint-address" or "current-endpoint-address" causing unnecessary system logs to be written.

where is this setting? I do not see it

is-responder (yes | no; Default: no

where is this setting? I do not see it

Using Winbox go to WireGuard / Peers
That’s where you will find Responder

where is this setting? I do not see it

Using Winbox go to WireGuard / Peers
That’s where you will find Responder

That feature wasn't implemented until 7.15 so you won't find it in 7.14.x.