I recently asked for help related to billing method issue and I received the following instructions.
1. Delete browsing history of your browser
2. Empty cache
3. Clear Upwork site lags using https://www.upwork.com/clearcookies
4. Use a different browser
5. Re-start/reboot your computer.
I followed all instructions but facing the same error. I used another browser. It first let me add my debit card but when I press for payment for upgradation then it gives an error. After that, it asks to update card information but when I try to update it. It says your card is not recognized. I contacted my back services and they said that everything is all right from their end. I used this time Microsoft edge browser and window 10.
I can see that you have followed up on your ticket and our team will assist you further directly on your ticket. If you have any additional questions feel free to follow up on your ticket. Thank you.