Font family automatically resets to default (Calibri) as soon as I start typing

Here is what I'm experiencing, in Windows 11:

• open a blank Wordpad document, type some text in it;
• select all, and set the font family to anything other than 'Calibri' (e.g. Trebuchet MS);
• put the cursor in the middle of the text;
• type some new characters.

Result: instead of keeping the same font family as the surrounding text, the new characters are set to the Calibri font face. The font size is not reset: only the font family.

This happens for me in Windows 11, but apparently some people already experienced that exact same behavior in Windows 10.

This is an issue that I initially encountered in the note-taking app KeyNote NF, but after raising this issue on their github, the dev pointed out that the root cause is more probably linked to the RichEdit component (control?) that ships with Windows (he wasn't able to replicate this behavior on his Windows10/11 machines). Indeed I was then able to confirm that this happens (for me) also when typing directly in Wordpad (which is also based on the RichEdit control).

Calibri seems to be the default font for several Microsoft products, so it seems like "something" triggers RichEdit to reset back to the default font every time I start typing...

(I do not have MS Office installed on my machines.)

Any idea what causes this behavior and how to fix it?

Some updates:

1. Following advices given in comments, I tried using the DISM and SFC commands to repair Windows. Although one file was find to be corrupted and restored (C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\mscormmc.dll), this did not solve the problem.

2. I cannot replicate the issue on my other Windows 11 computer. So this seems like a weird and specific bug related to some configuration on my main computer. Since I can easily compare the configuration of those two machines, I'll gladly take any suggestion about what to look for...

3. To clarify: I do not care about WordPad, nor do I use it, and I'm not asking for replacement editors (I know that already). WordPad is simply the simplest way to test this bug, which also effects other softwares such as (less known) KeyNote NF, which also relies on the RichEdit control (and which I use a lot). So the bug is probably located at the RichEdit control level, since it effects both apps (WordPad and KeyNote NF) in the exact same way.