Those symptoms might be caused by new interfaces constantly appearing/disapperaing and triggering routing protocol update scripts (ubnt-static.pl, ubnt-ospfs.pl, ubnt-bfd.pl...).
To troubleshoot this issue further:
- Enable debug syslog - set system syslog global facility all level debug
- Collect debug logs for 10 minutes
- Disable debug syslog - set system syslog global facility all level notice
- Show content of /var/log/messages
