Hi @Florin Iaru,
Thank you for sharing these clear screenshots and all the context. I understand how concerning it can be to find a character substitution like this, especially at the print stage.
I tested this on my end using InDesign 20.4.1 and wasn't able to reproduce the issue so far. Could you please confirm the exact version of InDesign you are using, for example, 20.4 or 20.4.1? It would also help to know if this happens in all files or just this one. When you get a chance, please try creating a new simple test file using the same font and hyphenation settings, export it with 'Create Tagged PDF' enabled, and see if the issue appears.
Additionally, please let me know your OS version and if you are using any custom font management tools or plugins. If possible, it would be helpful if you could share an affected sample file by packaging it, along with a short screen recording showing your export settings and the resulting PDF, so I can investigate further.
Looking forward to your update!
Abhishek