Unlimited plan restricted to 2 hours of calls

Hello everyone, so here it is, I have a Free plan at €19.99, so unlimited, and I have a small problem with calls. When I make a call, it gets cut off after 2 hours (I can call back afterwards) but the call stops after 2 hours. Being in a long-distance relationship, I call my girlfriend very often and every time the calls drop after 2 hours. I searched on the Free website, but I couldn't find anything, I want to specify that the calls are made in France, and in the services, I do not have a 2-hour limit. So if anyone has the same problem as me or knows how to fix it, I would be grateful if you could help me. Thank you in advance :)