Well you could try to generate a new config.txt but my gut feeling is the SD card failed so you might be better of by backing up your config from the card and do a new install on another card or at least test this card first with h2testw.
There has been reports of this happening with sudden power loss or some other unknown situation. Testing the SD is never a bad idea but I personally, assuming your still on Kodi v18, would just put the following in config.txt and see if that gets it going…
Some good news. Have over-written the micro sd with a new osmc image. The Pi boots…with ALL the old settings! TV Head end is in there, same ip, etc…etc.How did this happen?!
When some SD cards fail, the controller will fall over in to a silent read-only mode. This gives the illusion to the OS that data is being written but it is not. This is why your old settings and environment were persistent even after writing another image.