Description:
When opened not full screen, LO (whatever the app) displays only a small part of icons in its tabs, while there is plenty of room.
It's when you clic the "expansion" arrows to display hidden icons that you have at last the space in the tab bar filled with icons.
Please, see the enclosed gif for a clearer understanding of the issue.
Note the 3 phases in the gif : 
1) LO is opened an display only few icons, with a lot of free space
2) the expansion arrows are clicked, it shows the hidden icons
3) when I clic elsewhere, at last the free space is filled with icons.

Steps to Reproduce:
1) LO is opened an display only few icons, with a lot of free space
2) the expansion arrows are clicked, it shows the hidden icons
3) when I clic elsewhere, at last the free space is filled with icons.

Actual Results:
only few icons, with a lot of free space

Expected Results:
Tabs are displaying as much icons as it is possible


Reproducible: Always


User Profile Reset: No

Additional Info:
Version: 7.5.0.3 (X86_64) / LibreOffice Community
Build ID: c21113d003cd3efa8c53188764377a8272d9d6de
CPU threads: 16; OS: Windows 10.0 Build 22621; UI render: Skia/Raster; VCL: win
Locale: fr-FR (fr_FR); UI: fr-FR
Calc: CL threaded