Hi, @SupportiveEntity good to see you again, I am using windows 11 22H2, I noticed this happen on all of the unreal site, not only the document page.
My anti-virus software is kaspersky, I tried disable it but still the website lost the scroll bar once I press alt, don’t know if that’s the problem.
This happend on edge, firefox, chrome, I didn’t test other browser, but I noticed sometime I can press the ALT, TAB button freely, but it would randomly showes up after I refresh the page or open another document page.