My phone only connects to 2g networks

So, recently I had some water problem on my Moto X... I left it turned off for some hours, and when I turned it on everything was working fine. Except that it only connects to 'G' networks. Before this it only connected to 3g and 4g network, but now it seems to only connect to this 'G' network.

It connected to the 4g network once (after the problem), but it didn't last long. I'm wondering which part of it should I replace, since it appers to have way to many antennas (the nfc one, the lower and top antena).

Edit: Everything else is working fine, even the calls. The signal seems to be weaker, since it stays without connection sometimes now.

Any advice?