MFA Freezing

Hello all, we have been on about a year now and we seem to have an intermittent issue with members being able to sign in when registering for programs and event tickets. The email is initiated but the designated window to put the MFA code in just freezes and we have to close the entire window/cart. We have tried multiple browsers, operating systems, etc. It sometimes lasts for hours and in my case, I struggled with it for months which made testing web events difficult. Anyone else having issues and if so have you found solutions? Customer support is trying to help but without error codes or being able to send them more definitive information we seem to be at a stand still in finding a resolution. Any info/insight appreciated in advance.