the problem occurs only when the gearbox is hot.
i can feel a friction during changing gears. it's a kind of continuous friction during moving the handle up and down. no problem with gears changing, but this friction and the gearbox goes slightly harder.
i have such a feeling if when the lubricant is gone.
can it be the clutch problem?
other thing is that when i press the clutch handle i can hear a noise like “kwiiiiik2 from outside bottom part of car. it may be a cylinder.
i had a similar problem on my 323, got worse when the car was hot and in summer, i took off the gear linkage rodunderneath and greased up the pins which were trying to seize. been fine since. hope this helps