Hello Monika Nociarová,In this case, I'd say it would be better if someone can look at the situation directly so check it for you. Since the cause of the phone doesn't connect range widely, and it is not always the system issue with phone connect (connection is set as charging mode, cable only supports charging,..). So the best way is to have other look at it directly. Thank you for your understanding.
If you still want to check, you can try to use another phone and connect it using the same cable.