freeze & latency issue

Mac mini I7 2018 . Mojave
Cubase 10.5.5

its hard to describe this problem ,so i just made a video of it:
you can see it very good from sec 29 on.

so i work on that project for about 2 hours now and suddenly it freezes for some seconds after every action i do. Mouse clicks or play or stop or save. anything.
the only thing that helps is to close cubase and open it again. I have that issue every day and i wonder what that is.

i checked the performance monitor and there is still headroom in ram and cpu. no peaks

Another issue is:
after bouncing a track and again working in the same project somethings the mouse doesnt show the squares in the regions like to stretch a region or to fade in or out. i then have to click outside of cubase and then into cubase again to make it work again … very strange

do you have any ideas?

nothing? I also didnt get any response from the steinberg ticket system :frowning: