the bandwidth constraint seems small .. ex
22:57:06.021: Output 'rtmp multitrack video': Number of dropped frames due to insufficient bandwidth/connection stalls: 4537 (1.0%)
BUT
immediately follows a LOT of streamlabs related errors... why am I not surprised... I have no idea if one is causing the other, but working with streamlabs to clean up your config, or fix their system would be advisable, regardless.
but then you later have
22:58:30.398: Output 'rtmp multitrack video': Number of dropped frames due to insufficient bandwidth/connection stalls: 3465 (73.6%)
What are you doing for real-time network utilization monitoring at WAN link level?
Also, have you tested without your 3rd party antivirus running (or at least configured to not interfere with your livestream traffic)?
22:19:48.996: Sec. Software Status:
22:19:48.997: Bitdefender Antivirus: enabled (AV)
an AV 'issue' could easily be causing your problems. though that 'issue' might be triggered by streamlabs nonsense