I had this same issue and managed to fix it.
My default browser was google chrome and when logging in on the client it would redirect me to the website to log in. Although i was entering the correct information it would tell me it was incorrect, As soon as I switched my default browser on my mobile device to Samsung Internet, when redirected from the client to website to log in my information worked perfectly fine.
So for me it was a Google Chrome on mobile issue. Anyway hope this helps.
12-Dec-2020 10:49:36