When linking 2 transmitters to 1 receiver, only one of the transmitters will transmit the redstone signal to the receiver.
While it clearly shows both transmitters are linked.

That's a purely visual issue. Only one transmitter is supposed to be able to transmit to a receiver- 1 transmitter can have multiple receivers, but one receiver can only have one transmitter.

The bug is that both transmitters looks linked to the receivers, when the other should visually unlink.

Ok thank you. I later looked at the code and drew that conclusion aswell but i was not completely sure