I thought I was having this issue with my scope and wrote out a long reply. However, I fixed it before I hit post, haha.
The issue I was having was I plugged in my CAT6 to capture screens of the scope, but I didn't update the IP address of the scope to match the app (moved recently). When I opened up the FFT with a pure sine wave coming in, it would freeze every time after about 2 minutes. Then I realized the IP error and I went in there first (turning off FFT after restart) and after I corrected that, I no longer have the button freeze issue.
This is still an issue that Siglent should address though. It was doing this before I ever opened up the application in Windows and even if someone has the IP wrong, it shouldn't freeze up the entire button assembly, forcing you to pull the plug.
It has to do with FFT + external I/O that is causing this to happen. Hopefully they figure it out soon.