Bounceback monitoring updates contact, but doesn't reflect in email logs/graphs

Your software
My Mautic version is:4.4.10
My PHP version is:8.0
My Database type and version is:
10.6.16-MariaDB-0ubuntu0.22.04.1

Your problem
My problem is: Bounceback monitoring updates contact, but doesn’t reflect in email logs/graphs.

These errors are showing in the log:
Tons of these that I think are unrelated since I don’t use webhooks:
2024-03-13 18:40:06] mautic.WARNING: Command mautic:webhooks:process exited with status code 1 {“hostname”:“mauticapp”,“pid”:4453}

[2024-03-13 18:42:06] mautic.WARNING: Command mautic:webhooks:process exited with status code 1 {“hostname”:“mauticapp”,“pid”:4552}

Steps I have tried to fix the problem:
rebooting the resource and trying again
enabling raw message delivery on AWS SNS - broke monitoring completely
Added delivery+complaints SNS topic monitoring - no change.

Noting that when I navigate to the callback URL I get a

"Oops! An Error Occurred

The server returned a “500 Internal Server Error”.

Something is broken. Please let us know what you were doing when this error occurred. We will fix it as soon as possible. Sorry for any inconvenience caused."

Any ideas? I will update with any additional attempts or potentially relevant details. Sorry if this is a duplicate post.