I had some plants do this just recently. One got sick and the ones directly around them all just went to shit slowly but steadily. I couldn’t get nothing to work. I chopped the last one just yesterday.
It was a reveg plant that I had liked and wanted to keep. She came out of flower and vegged out quickly and easily. Then for, whatever reason, I couldn’t get a clone of her to take. I tried and tried everything I knew and nothing produced calluses let alone roots. I put her back in flower and things just went down hill. I had figured it was from my neglect, not getting on top of it quickly, but I also had 3 other plants that were around her that weren’t able to make it to harvest either. None of this is typical. I’ve had life kicking my ass lately so I’ve been less on top of things.