Mindjet files very slow in loading files, and often read-only

Files stored in Mindjet Files are often very slow to load.

And often the file is locked to read-only, directly on open or after a while of editing.

Network issues have been investigated, no problems.
Files have been saved local, and re-saved in Mindjet Files. Still same problem.

Now the problem is getting bigger and bigger, Mindmanager almost impossible to work with (MF used all day).

Any suggestions?