International LG G4 does not connect to LTE after drop to 3G

I have an international LG G4 H815 on T-Mobile and the LTE works perfectly, but after it drops to 3G to connect to an incoming phone call, it won't want to connect back to 4G LTE even if I manually select LTE in the select networks menu.

Only a restart or selecting "LTE only" in the engineering screen clears the issue(but with LTE only I can't make or receive phone calls or send or receive text messages) but it is very annoying and I was wonder if anyone else had this problem.