I see, a few thousands time per day, the log warning : WARNING: No SCM configuration was found! in the monitoring plugin. 
It's : 

May 20, 2025 11:53:11 AM WARNING com.cloudbees.jenkins.plugins.BitbucketJobProbe triggerMatchingJobs
No SCM configuration was found!
I do have multiple projects, using bitbucket, and webhooks. It seems, properly set and working, has been there for a few years without particular issues. 
I do not see anything specific in the logs, that could point me to a particular payload, particular project, or so. 

Would you happen to have more details on what conditions would trigger this log message, that would help pinpointing the issue ? 

I flagged it as Major, as the source is yet unknown, and it creates several thousands of log lines per days, flooding it.