Stiff transmission and truble with resetting transmission linkage

Hi

For some time, my Skoda Fabia MK2 have become stiffer and stiffer when changing gears – especially going into reverse.

I found out that I might be able to fix it with a transmission linkage reset. But that didn’t fix my problem, even though it might have brought me closer to finding the problem.

I followed the guide in the Haynes manual and this video when doing the reset: https://www.youtube.com/watch?v=cCFpbcFyVHI&ab_channel=AlanMcRae

But I couldn’t compress the shifter (A) enough to lock it in place. But when I moved it, it squeaked a lot(!) Not like metal rubbing against metal but more like plastic against rubber.

I don’t know if I need to get the transmission changed by a mechanic or if I can lubricate my way out of it?

I watched a video saying it might be the pin (marked with the blue circle) that is rusted and stuck? But it didn’t feel like that.

nb: I know that there are topics a bit like this one the forum, but i haven't been able to find one that matches my problem exactly.

Best regards
Mathias