On a quick inspection I'd say it's because the criteria for numbers matches but without the dashes, you have spaces instead.  But t's a bit of a guess because using this alone may not be representative of what you have in the sdlxliff or what Studio may be doing (it's always possible Studio is simply wrong and it's not your rule at all):

F754 8 cm Pfoster

If you can share the file, at least with that segment in it, I'm happy to take a look?

Paul

I sent you the file by email.

Daniel

The Unicode \p{Zs} and \p{Pd} character classes for space separators and dashes, respectively, can be used to avoid the need to write a list of Unicode characters.

Not the answer to your question, but I'd like to comment that if you delete both the leading and the trailing [\d,]* , the resulting regex will match the same segments as the original regex. So you can simplify a bit your regex.

Jesús Prieto

You are right. Can be I once had a capture group there - I use these regexes in different situations.

Daniel