Server crashing after latest update to 1.15.0 - Logs included

Yes both useful - the logs and db

The logs show two issues
One is the crashes and that is being investigated by the development team,
You had 9 crashes in 3 day period

The other issue appears to be to do with time to process requests and access the sqlite3 database. Requests and actions are taking far too long to process and leading to timeouts and client app failures

Having seen the database i can understand why - it is a 3Gb database with a million items. Is this on SSD Drive? If not, you should consider it
and also run a database optimize -see library actions
https://support.plex.tv/articles/200392106-library-actions/