NHS mail no longer letting me log in

Question probably most relevant for other NHS mail users!

Up until about a month ago, I was able to access my NHSmail through Brave without a problem. Since then, it has stopped working. When I go to portal.nhs.net, I can click on the blue ‘Access Email’ icon which takes me to the sign in page. I enter my log in details but then instead of getting to the OWA page I get an Error 401 with the message “If the problem continues, contact the site owner”. I can still log in to my NHSmail on other chromium-based browsers so it’s not a problem with my log in details. I have cleared the cache from Brave and also uninstalled and reinstallled the browser but this hasn’t resolved the issue. NHSmail helpdesk have told me it’s a broswer issue, I’ve been hitting the ‘report broken site’ every few days on Brave but it hasn’t sped up resolution of the issue. Can anyone tell me if it’s an issue with Brave or an issue with NHSmail?