Catalina - Display-link previously worked - now it picks up monitor but black screen?
 

Catalina 10.15.7 - Intel MB Pro - 3 screens - all 3 rotated 90 degrees and all 3 working perfectly until today. 2 screens using direct usb c connections and the 3rd one using display-link. No o/s updates downloaded.....

So for no reason whatsoever my third Dell screen is now black. Display-link is picking it up but the screen is black. I have unplugged, disconnected and reconnected everything to no avail. The screen works - its just Ive re-downloaded the Display-link Catalina version which is now showing the screen in landscape mode - but its still black and now I cant rotate it (even if I could see it...). Any ideas on (i) how to see my display-link screen again and (ii) how to get the rotation back when I do (I think I may have previously installed an older version even though using it on Catalina)

Finally - haven't upgrade from Catalina - as everything was working perfectly and didn't want to mess things up - but is it now worth upgrading ? Im on an intel based MB Pro - thanks in advance !