Hey,

I had this problem one time. I fixed it with left mouse click on the client, afterwards clicking on settings.
Then click on compatibility, then u see compatibilitymodus,
try different types of Windows on the miniclient (for me Windows Vista compatibility fixed it).
If you cant change the compatibilitymodus, run it as administrator.

Best of luck~

Hello, I have also experienced this issue when the main monitor is set to a resolution above 1080p. You might also want to try dropping the resolution while playing, if Aika's fix did not work for you.