Description is here: 469275 – Non-removable volumes shown as removable volumes - still reproducible with latest SUSE/KDE release.
I checked a TW desktop, a TW laptop, and a MicroOS KDE in a VM.
All removable and non-removable devices are shown, and not shown, as appropriate.
Might do a couple of things:
a) System Settings → Removable Storage - check those settings.
b) Login with another (new) user - check the Devices widget.
You should answer the request in the bugreport…
a) Read the report first: System Settings is fine!
b) Same bug
Also removable media is not shown in Dolphin - only HDD or SSD.
udisksctl dump attached there.
Yes, I bought new MB, bug started after that, so https://bugzilla.kernel.org/show_bug.cgi?id=111651#c3 helped:
Disabling the hotplug functionality in the bios make the drives appears as non removable anymore