My ingame nickname is Ghastier. Today afternoon I noticed something wierd when upgrading the magnum turret. I was a player who returned after a pretty long break so I noticed the upgrade system got changed such that we cannot upgrade a turret from mk3 to mk4 in a single click, instead we needed to get all the smaller upgrades (mk3-1, mk3-2, etc.), and pay tankcoins to finish it. The wierd part is, at mk3 onwards, I was still spamming enter and click to upgrade the magnum turret (My target is mk7), but the upgrades got to like mk3-40, and it costed LOTS of crystals and I stopped there. I was not sure if it was a intended feature or bug, but I did know that there were changes to upgrade system. In the evening, I entered the game again, the magnum turret was lowered to mk3-0, but the crystal spent was gone. I logged in again but its still the same. When I upgrade it, it becomes mk3-1. In conclusion: I losted all crystals used to upgrade the magnum to mk3-40 (which was probably a bug?) Unfortunately I did not take a screenshot of the mk3-40 magnum. However, I am not lying, it really happened and I hope the developers can check my activity history (if possible). I will be attaching a screenshot of the mk3-1 magnum below.