Problems with Leap 15.5 KDE

In addition to the "shaking" video problem I mentioned earlier, there is another severe problem.  After 2 or 3 days, my desktop will lock up solid and the only way out is to kill the power.  It is only the desktop that locks up, as I can still use SSH to connect and do stuff.  After a few lockups, I went back to 15.4 and both these issues stopped.  I then returned to 15.5 a few days ago and both problems returned.  If there is no resolution soon, I will be forced to return to 15.4 again. Since that hardware module is no longer in Yast, I can't use it to provide hardware info, so I can only read from the box. The motherboard is a Gigabyte H77M-D3M with an i7 CPU.