Gear lever stuck in gear

I experienced strange problem with my car. My gearbox lever was stuck in first gear while I was driving, it didn't want to move to second or neutral. Few seconds later I pulled it down to second gear and everything was ok for about three minutes. Then same thing happened. I drove my car to my Renault Dealer to check my car up because I just bought it and I wanted to be sure everything was okay with it (it has 190 000 km on the clock). After check-up, they said everything was fine with my car and that I shouldn't be worried because of my problem with gear lever. Next three weeks my gearbox (gear lever) was acting completely okay and very smooth, I was very satisfied with how it works. But yestarday my lever didn't want to pull out of second gear. I did make gear change ultimately so I stopped and turned off my car. Half an hour later, I started to drive again and my gearbox was acting perfect again.

Anyone know what the problem might be? I have heard it is a common thing with Clio III gearboxes. Teeth sometimes get one by one and because of that I can't move my lever. Is it truth?

Thanks.

Gear lever stuck in gear