There are two results you are seeing. 1) Unknown words are getting marked with an @. That’s expected. 2) The number ends up with space after the comma. This is the by-product of FLEx seeing the comma as punctuation and dividing the number into two words. I don’t think there’s much we can do about it.
I suggest a workaround by using a text-out rule to remove spaces after a digit then comma and before a digit. The rule would look like this:

As for the @ signs, there’s a couple options. I saw you had a text out rule that removed the @. That works. Or you can use the setting shown here to automatically clean up unknown word symbols.

The advantage of this is that it will also clean up cases of a word with numbers after it. E.g. lieben1.1 > lieben.
Using either method, you can control what you see in the Live Rule Tester’s synthesized with the following checkboxes.
