I think it's mostly related to the internet connection speed, i've tried with 3 different line ( here from italy we have slow internet connection ).
The game is played with an Iphone SE IOS 11.3.1 using Safari
From my house ~4 MB Down ~0.2 MB UP: Nearly impossible to use the game
From my house using LTE data connection of my phone ~15 MB Down ~ 10MB UP: Everything is OK
From another house ~10 MB Down ~0.4 MB UP: Almost fine, the error is still pesent but rare
From my office ~ 30MB Down ~ 3 MB UP: Everything is OK