I have been using this Eleaf Invoke since November 2018.
Shortly after the purchase, the Battery Door started to slightly open on its own, but never to the point of dropping them on the floor.
After messing around with a few solutions I found online, I ended up making my own fix a few months ago.
Here's how to fix that trapdoor ! :)
Check out my Youtube Gaming Channel https://www.youtube.com/channel/UC_veaCt7tNekT3j5R9XEj-g ;)