Hey upwork, you should put this bug on your highest urgency level.
For an international platform this is very annoying. I have the same problem. Seems like because my name is written with an "ö". Now I can't use PayPal and have to use my Credit Card, which means I have to wait some days to verify.
The problem seems to be solved when one updates his contact information, as suggested.
Please change the error message, indicating one has to go to Settings > My Info etc. - and people will get it
I see that you have been on a live chant and one of our customer support agents assisted you with this. If you have any additional questions feel free to post them here, thank you.