OpsCenter 8.1.1 database busy after restart of service

Windows Server 2016 Std + OpsCenter v8.1.1 - it's a pretty small setup, only 1.8 GB in the main database file.  Was upgraded from v7.7.3 about six months ago.

Anyone else seen a problem with "dbsrv16.exe" chewing the CPU after the database service gets restarted - which effectively breaks the OpsCenter application for like 20 minutes - because the OpsCenter "server" service is unable to talk to the database server.  The app is fine after about 20 minutes when dbsrv16 returns to normal levels of CPU activity.

Nothing obvious in server.log.  However, I saw "I." (info) messages in server.log re fragments for two database files.  So I ran dbdefrag, which did not resolve the issue of dbsrv16 high CPU and unresponsive app.  All the dbdefrag has done is to quite literally triple the fragment count, and the dbdefrag has now fragmented two more additional database files.  Perhaps the script should be renamed "dbfrag".

Anyone got a solution for a silly dbsrv16 for around 20 minutes after restarting the service ?