After the update 10.5, some ports indicated in the screenshot missing. This notice appears in every my old projects cubase 10.4
But in audio connection evrything is ok
This is normal. Also in older versions. Just remove the tracks that you don’t intent to use anymore or ignore it?
Or if you know what port that should be you can permanently map it to that port in the dialog in your pic. You’ll need to do it for each old Project when you first open it, but after that you won’t.