Spaces missing before SOME glossified words with special characters

Ok I think I found the reason: PREG_OFFSET_CAPTURE does not support multibyte!

It's used in:

preg_match_all($pattern_part, $text, $matches_part, PREG_OFFSET_CAPTURE);

https://stackoverflow.com/questions/9950842/how-to-get-correct-list-posi...

Okay, this still might be wrong, but the root cause in our case was code like this:

This is my<strong> Glossify</strong> text
resulting in
This is myGlossify text, so spaces were removed, because they were part of the inner wrapped word.

I've created a more precise follow-up: 🐛 Glossify removes spaces in unconventional wrapped terms Active

So my case was totally unrelated to multibyte handling.