Have you open a trouble ticket at support@mikrotik.com as I've suggested 1.5 years ago? In your setup, does the issue appear between two Mikrotiks or between a Mikrotik on one end and some other IKEv2 implementation on another? I haven't noticed a single occurrence of that issue during all that tim...

1.5 years passed and this issue still exists)

Looks like this issue isn't really fixed, I've tested 6.43.4 and 6.44beta28 IKEv2 in transport mode proposals: add auth-algorithms=sha256 enc-algorithms=aes-256-cbc lifetime=1h pfs-group=modp4096 profile: dh-group=modp4096 dpd-interval=10s dpd-maximum-failures=3 enc-algorithm=aes-256 hash-algorithm=...