Really, you should investigate those two
[2022-04-07 17:09:15] (XEN) Built-in command line: ept=exec-sp
[2022-04-07 17:09:15] (XEN) parameter "no-real-mode" unknown!
Carefully read both explanations on the xen-manpages :
Simply put : don’t use them.
You tried freq-scaling stuff, what exactly ? Remove your tests.
Try using/re-installing the Xen version provided by Qubes, and the stock command line.
Xen affects number to machines internally. d1 is the first domU/VM started (use xl list to get the id).
Try not using the wifi card.
You could try other distros, like live ones, to see if those bugs happen too.
You can even try a live distro that can be persistent, and on which you install Xen.
When debugging a problem you should remove everything first, then add things.