I am usually pretty good at putting my lipo back to storage charge when I am done with them for couple of weeks, but recently I noticed that my dual charger doesn't seem to be able to storage charge two batteries at the same time. Is that a thing ? i.e. it juices out and can't storage charge two batteries at the same time ? I never had any issue with dual charging and still doesn't.

Could be a cooling issue. If discharging down to storage charges, it needs an way to use power to create heat as part of the discharge portion. Too much heat = shut down?

Also depends if a cheap banggood/aliexpress knockoff of a good charger...

Thanks Mike......... It does have a fan at the back. I am slowly coming to the conclusion that one half has stop working when it comes to storage charge. Will pay more attention and see if that is the case. Up to now I just figure it is specific batteries.