I am also noticing this on two home assistant setups. The currently using deCONZ 6.5.0 with ConBee II as the Zigbee hub on both.
Checking the logs:
Logger: homeassistant.components.recorder
Source: components/recorder/init.py:509
Integration: Recorder (documentation, issues)
First occurred: 7:08:55 PM (405 occurrences)
Last logged: 8:39:54 PMError saving events: (sqlite3.DatabaseError) database disk image is malformed
Background on this error at: Error Messages — SQLAlchemy 1.3 Documentation
Update: this lead me to a good thread:
In short: ssh in, delete the db (yes, along with it all history) and then restart HA.