What I did this morning while checking something else, was to choose month by month. Not sure if it allows you to choose few months at a time...
It's really strange. Maybe someone who happens to be at JB Sentral can ask the staff about this. I've no upcoming trip planned and I've switched to 2nd Link for a while already. Used to visit the counter at TF Value Mart in Nusa Bestari, but stopped going there since they removed the bus stop.
Edit : I know last time, like preC19, I'd encountered the 6-month validity issue a couple of times. But sometime after the ability to add the cards to Lugo for easier management, I did read somewhere about the removal of validity...