Cannot log in to online banking using Firefox

The credit union I use has made some changes to their website and now I can’t log in using Firefox which has always worked before. Complaining to the credit union about it has not helped.
Clearing cache and cookies, disabling Malwarebytes Browser Guard have no effect.
Any suggestions are appreciated. Thanks

Hello and thanks so much for getting in touch. I’m so sorry that this section of the forum supports the Common Voice project and is run by the Mozilla Foundation and that we don’t overlap with the Firefox team or their support capacity.

You may be better served checking the Firefox support portal here, as they’ll be able to help! https://support.mozilla.org/en-US/products/firefox