As far as I have found, this is not a KDE or OpenMandriva thing, but an application specific feature. Like in Konsole, you can configure to hide text or display text alongside icons, same with Kate.
If you go to any KDE application and you want to add text to a button, nothing happens. On the first picture you can see that checkmark for hide is removed and that didn’t do anything.
Checked again in both Kate and Kwrite. For me, Kate did not have the issue you describe, but Kwrite did. I solved it by doing this: Settings → Toolbars Shown → disable Main Toolbar → reenable Main Toolbar
After doing this, I was able to change icon size and text position in Kwrite. I installed Kwrite on my openSUSE install and had the same issue.
Click on the tools line and unselect hamburger menu. Click on icon line and select icons and text.
Edit: This problem should get a proper bug report if you want this fixed globally. But keep in mind that these days a lot of folks prefer what they believe is a cleaner look. Icons and text may be for old farts. I am suggesting that this may be on purpose, don’t know,
Operating System: openSUSE Tumbleweed 20250109
KDE Plasma Version: 6.2.5
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
Kernel Version: 6.12.8-2-default (64-bit)
Graphics Platform: X11
Processors: 20 × 12th Gen Intel® Core™ i7-12700
Memory: 31.1 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2
Manufacturer: Dell Inc.
Product Name: XPS 8950
I can’t C&P the same from the other PC, but it fails as well.
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
I tried @LeeTalbert’s method and I was not successful.
I had never tried to change the text on a button before, so I cannot verify when it stopped working, but I am guessing it happened with the change to KDE Plasma 6.0 and I know they are still working on getting some things working again. 6.3 should be released any day and maybe that will fix it.
I found the same issue in Konsole. So it does not occur in all KDE application, at least on my laptop it doesn’t. The work-around I posted earlier worked for me in Konsole as well, but as we saw above it does not work for everyone. For the record, I am on Wayland.