OUTLINE/STROKE Issue inside font/letters

Hello Community,

I have a very strange problem which appeared out of a sudden last week.

As you can see on the attached image:
When I use a certain font and put an outline - then the outline shows every single bar of the letter.

It is a google font "EXO 2.0" which we use as the main font for our company for years now. We never had a problem with this font.

Here's what I found out during my own troubleshooting:

I tested it on another computer with the same ILLUSTRATOR version: Problem does not appear

I deinstalled Illustrator and reinstalled the latest version: Problem still appears

I downgraded to an older version of ILLUSTRATOR: Problem still appears

I deinstalled and reinstalled the font: Problem still apears
Problem does not appear in INDESIGN

Problem does not appear in PHOTOSHOP

The problem appeared suddenly especially with this font - other fonts work like expected

I already contacted the designer of the font - no answer so far.

I tried a google search for a similar problem - I tried german and english but couldn't find any similar situation except one where someone asked the same question but didn't get an answer that helped.

Since it i our main font we use for our company - this problem gives me quite a headache - any help is highliy appreciated!