HOS there was nothing wrong with the batteries it is how they are prepped at set up time.
I was taught how to correctly prep a battery and mine lasted 9 years!
The least I got out of one is 5 and that was a wheeler that I didn't use much.
There is a proper way to fill a dry battery.
You should pop the bottle on the battery to break the tin foil seals.
Let it completely drain. Let it take as much time as it wants. DO NOT BE IN A HURRY!
Then look down inside. If you see liquid, let it sit until it looks dry. This is what most do wrong.
I am told once you put the cover on the battery, if they aren't fully absorbed they will never absorb.
They will only be partially functional.
I had one take two days to fully absorb!
Most don't take that long.
Then a very low charge no heavy charges. 1 amp or less until fully charged. Then and only then it's ready for use.
As far as why Geezer your bike is having this problem, I'm not completely sure, but by taking the negative off your battery and letting things reset, it might fix your problem.
I had that happen once a long time ago, and that fixed it thank God!