Cursor jumps to first page after a while

Hi!

This is kind of a odd situation, whenever our users are using collabora, after a while of inactivity, the cursor+doc jumps to the first page/first “letter”.

The strange thing is that I get two different cases:
*UserA gets a semitransparent inactivity message -after a while-, that can be clicked away, cursor stays at last position. (good)
*Then after an other inactivity, a dialogue shows up saying that “userA has joined.” (while document is solely opened by userA) then the cursor jumps to the first page. (bad)

Does anybody knows about this behaviour, what could be the reason for that?

Cheers.

I am using CODE 3.2/ installed via docker/ ubuntu 16.04