I didn't specify a version, as 5.2.3 wasn't an option.
As (I don't know why), the context menu disappears in 90% right after opening it with the mouse, I always used to open it with keyboard for i.e. moving a message to spam-folder.
While everything works as expected in all other parts, on the messagelist the menu isn't shown when using the keyboard.
Steps to Reproduce:
1. Go to message-list
2. Hit the contextmenu-button on your keyboard
The context-menu should be opened