Let me please jump in this conversation.
We investigated the plugin work on the popup on mobile devices, and have found the reason of such visual behavior of the plugin, which you have reported.
The main problem is in the libraries of the plugin and bubble popup element. This is quite fixable but requires a significant amount of time and dev efforts. So, unfortunately, at the moment we can see no opportunity to fix this issue rapidly, but, for sure, we have taken this point into the account and scheduled the works on the plugin improvement.
I can not provide you with the exact time estimates on how soon the plugin improvement will be done, but be sure that I will let you know once there is any useful update.
Apologies for such inconvenience. I suppose it is better to refuse from using the Phone Formatting plugin element in the popup for now