Text Style in Button Defaults in Test Email - Inconsistent Issue

Designing an email and have button color set to #22313f and text within set to 20pt bold white. The designer and preview window shows this style correctly but the received email in Outlook Web reset the text to black, arial, 14pt. However, I have 5 buttons total in my email. The 3 with this issue are in a single column setup but the buttons with the same styling in a 2-column system don't change like the above. So 2 of 5 buttons properly retain their set style. The button style works consistently on iOS Mail, Outlook Desktop for Mac, Outlook Desktop for Windows (minus the rounded corners).