[SOLVED] MIDI thru & record stopped working

Device setup looks ok
Preferences/MIDI thru and filters look ok
Midi input indicator reacts to key presses etc.
Midi-ox shows correct midi messages coming in on on correct channels.

No midi gets to vst synths or recorded from any input, keyboard or controller.

Been running the same setup for some years, but never seen this before.

What should I check next?

Is this affecting every project? Any difference if you start Cubase in Safe Start Mode?
https://www.steinberg.net/nc/en/support/knowledgebase_new/show_details/kb_show/safe-start-mode-resetting-the-cubase-preferences.html

Thanks - going bat poop Cubase (start Cubase, while the launch splash is up, keep ctrl+shift+alt pressed to get to the safe mode (?) panel and then delete preferences) worked.