Bug 461476

SUMMARY
Installed latest KDE neon 5.26 updates;  Windows misbehave when maximized:

So far the following are affected:
(I started seeing this with Konsole because I live there. I've tried other applications and include them here.)
 - Konsole
 - Okular
 - KeepassXC
 - KInfoCenter
 - KRDC
 - System Settings
 
Unaffected:
 - Dolphin
 - Brave browser

None of them updates the window when max'ed.  It takes input and produces output but nothing
changes in the window is restored.  

OK, I give up. I'll stop maximizing ;)


Konsole STEPS TO REPRODUCE
1.  Maximize windows
2.  Enter a shell command
3.  Restore window

Konsole OBSERVED RESULT
Window updates with shell command and result only when restored

Okular STEPS TO REPRODUCE
1. Maximize window
2. Click to open recent file: Doesn't accept  click
3. Click Menu to open file: File opens in another window but isn't displayed  
4. Alt-tab to new window shows only the window title until it's restored
5. Restore window and open a file
6. Maximize and try to scroll. Window doesn't change
7. Restore window and see  that scrolling did, in fact, occur
 
Both EXPECTED RESULT
Updates in realtime

OTHER NOTES
Menus and hotkeys seem to work, but no window updates occur until the
window is restored.

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.26
KDE Plasma Version: 5.26.2
KDE Frameworks Version: 5.99.0
Qt Version: 5.15.7
Kernel Version: 5.15.0-52-generic (64-bit)
Graphics Platform: X11


ADDITIONAL INFORMATION
I flagged this as "minor" because there's no "weird" severity. The workaround is simple:
Don't do that. 

I max most everything for focus and everything remembers to re-max when I open a new window.

*Addendum:

Well, nuts. I just opened KInfoCenter and it opened maximized and worked fine.
UNTIL I restored and re-maxed.

Ditto with System Settings.

I got nothing...