Trouble joining an external Viva Engage network

We are having similar issue with external users who access our SharePoint site / Viva Engage. The external users are added into Azure/Entra with B2B and we had no issues - we have a join process where they submit their email, a PowerAutomate flow checks that they are a B2B user in Entra, then adds them to the Group. We have challenges with users logged in with gmail using a one-time passcode. Until recently they were able to join/view the Community, but now it is returning errors, as of approximately 1st week Feb.