I just compiled hamlib and wsjtx on Ubuntu 20.04 and amazingly, it completed the process. It took about 2 hours of focused effort to copy and paste the commands from the webpage:

https://sourceforge.net/projects/hamlib-sdk/files/Linux/Ubuntu/

It involved downloading gigabytes of libraries and something called Qt 5.15.2.

After it compiled and installed, I simply typed in a terminal "wsjtx" and it executed!! I am able to feed in the audio from the Xiegu G90 (no cat control, just audio going into the microphone jack on the laptop and "rig" is set to "None" in WSJT-X "Settings" dialog) and see a beautiful waterfall display and piles of stations pouring in on the band activity pane.

With htop running, and I press "Tune" for the first time, the CPU usage was normal, but I did not check to see if there was audio coming out of the headphones port. But now when I run wsjtx again, the CPU goes to 100% as soon as I press "Tune" and I have to kill it using sigterm on the htop interface.

I can also click on "Tune" button again and it goes out like expected BUT the CPU is STILL pegged at 100% AND the waterfall display halts AND no more stations coming in on Band Activity pane. The lower left status box shows "Receiving" on a green background.

and the animated blue countdown bar in the lower right (1 through 15/15)is still going.
One time on the original "canned" install I saw the lower left status box say something like "Tx Watchdog timeout" with a red background. Maybe that is a clue??

I could REALLY use some help. I tried to make a boot-able flash drive with Andy's Ham Radio Linux and that went nowhere since I could not make the flash drive bootable even with Ubuntu 20.04's nifty "Startup Disk Maker" tool. I do not know how to download the ISO file to Windows7 laptop and make it boot off of that.

The canned wsjtx which I had initially installed had essentially the excat same problem as the freshly compiled version with the latest everything on it. I am stopped at this point.

Asus K52F running Ubuntu 20.04.

Do I need to use a different laptop? Should I try to install Windows 7 on my laptop and leave Linux? Should I install WineHD on Ubuntu??