Mac Mini 2019 after uninstalling switchresx

I have a mac mini 2019 and did a migration from a iMac mid 2011. have linked the two with thunderbolt to use iMac 27" screen in target display mode. I had it working fine. then i needed a longer thunderbolt cable so returned the short one for a longer one. meanwhile did share screen but had problems with the resolutions so installed SWITCHRESX to try it and then uninstalled and now can't get the line working i just get a blank screen black. and the sharing of screens now sees 4 virtual screens.

How do i get rid of the virtual screens from switchresx so i can once again use target display

under system preferences the display arrangement shows four thin displays and the scaled resolutions shows 1280 x 1024 and 800 x 1244 and the air play pull down menu show minor unknown display 1,2,3,4 for each of the 4

please help if you can