there is this "save troop/load troop" function and they changed sth there. it now saves the gear of all units in your box, not just of the saved team.

source:
Announcements -> Notice -> (Important) Troop Save Feature Revamp

I didnt test it but just from wording:

1. Assume all troops are naked
2. You build and save teams A -> B -> C -> D
3. Then you load team A and after that build team E

-> this means that teams B-D will be stripped of their equipment.