Roaming doesn't work

Hi! Since day one my EU roaming doesn’t work No calls or mobile internet use possible. I tried all the solutions you can find on internet and nothing worked so far. Deactivated and activated it, tried to use only 3G, tried to choose provider manually, tried on different phones, restarting phone when crossing borders and nothing...Im based in Germany and mostly travel to Poland so nothing really exotic. My wife also has the same problem and we made our contracts with O2 pretty much at the same time. Pls help :)