Hi
The issue is the function DbDel which had been depreciated since Asterisk 1.4 has now be removed, at least in Asterisk 16.

so in
/etc/asterisk/extensions_override_fop2.conf

this two lines must be changed

192: exten => *79,n,Noop(${DB_DELETE(fop2state/${CHAN})})
267: exten => *76,n,Noop(${DB_DELETE(fop2state/${CHAN})})

Please change in the next update

THX

http://forum.fop2.com/4691-dnd-broken-since-installing-2-31-21

Same issue. At the time I didn't realize the cause was Asterisk 16.

This is still broken.

dbDel is still used in the DNDOff scenario.