problem with sound in 161in1 cartridge

I have 2 mv1f bases working perfectly (image and sound) with my mvs carts.
But when I try to play a 161in1 cartridge, there is no sound.

Strangely, when playing this same 161in1 cart in a mv1c base, sound is fine.

Any idea what is going on?

Honestly if you haven't tried cleaning the slots on the 1F's and it still doesn't work... say hello to cheap chinese shit being... well shit.

Yes, I cleaned the slots on both mv1f bases.
When asked the seller, he tells me that the mv1fs are too old.

I really don't understand why it's working only in some specific bases ...