Right end of main toolbar background is white despite using preinstalled theme. The left end follows the theme. It can be workaround and look correctly. Please see attachment before the workaround (looks bad) and after the workaround (looks good).
Steps to Reproduce:
1. start calc
3. Click on "Gray theme"
3. View->User interface->Single toolbar
4. restart calc ("Single toolbar" can show correctly if one had other option selected earlier so restart is needed)
Right end of the "Standard (Single Mode)" toolbar's background is white.
The above mentioned background should look according to theme.
User Profile Reset: No
OpenGL enabled: Yes
1) the issue doesn't exist if I choose "View->User interface->Standard toolbar" but that works only in calc and not in writer
2) the issue is present in calc and in writer
3) to workaround the issue in calc choose "Insert->Chart..." and then cancel the dialog that opened (wrong white background switches to correct theme background after that)
4) it happens on other preinstalled themes as well, e.g. on pink theme
5) It's Plasma KDE 5.17.5 on Fedora 31.
6) My screen resolution is 1280x800
7) My gpu driver is nvidia 340.108
Created attachment 158271 [details]
Toolbar's white background
Icon theme used is Tango.
Confirming, the Notebookbar theming is not redrawn on resize. That's a bug.
*** Bug 137516 has been marked as a duplicate of this bug. ***
*** Bug 137796 has been marked as a duplicate of this bug. ***
*** Bug 137791 has been marked as a duplicate of this bug. ***
*** Bug 138107 has been marked as a duplicate of this bug. ***