a poorly designed A/C system will do the exact. i feel like your is just of an extreme

the "correct" way to fix it is to redo the ducting. Getting rid of the older circle or box style splitters and using triangle ones. Trying to even out the lengths of ducting as much as possible without wraping.

BUT the duct limiters should work...but is a quick and dirty method. You will gain some heat energy from the lack of "good" flow