If you have two power armors with different durability and ctrl+click them to your equipment slot and back, they are swapping durability.
You can use this save https://forums.factorio.com/forum/dow ... hp?id=5476 for testing. Just ctrl+click equipped armor to inventory.
[0.12.8] [kovarex] Power Armors swap durability on Ctrl + Click.
Re: [0.12.8] [kovarex] Power Armors swap durability on Ctrl + Click.
Thanks for the report, it is fixed for 0.12.9
Re: [0.12.8] [kovarex] Power Armors swap durability on Ctrl + Click.
Actually, considering the general way things like that should behave, I decided to revert the fix, and leave the behaviour as it is now.