Hi Abi,
I run a club full of mobile players, also play in the coin rooms myself, and I haven't heard of or seen this as a recurring issue. When it happens to you, do you have a dodgy internet connection? You could also try deleting the wgt app and installing again, see if that helps.
If it keeps happening you could record your screen while playing, then when it happens you can upload the vid somewhere and send a link to customer service. They can't argue with proof.
Good luck!
Mick