This has been bothering me for awhile now, but only just got around to asking about it. Whenever I build a team via the Troop section, the game doesn’t seem to save my team. It only does so for me if I make the changes in the pre-battle screen.
I have the same issue, but weirdly not all the time; sometimes the game actually remembers my teams. 1.0.8 will fix every problem in the world, I’m a believer!
The most reliable situation seems to be, make a change in the troops menu, then go to the pvp menu, then go back to the troops menu the changes made in the second (and subsequent) trips through the troops menu stick. There also seems to be a point where you have done “enough” in the app that the troop menu starts saving properly. I haven’t quite worked out what “enough” is, but it seems to be most linked to going into the PvP screen (regardless of whether you have visited the troops screen or not previously).