Hello Enric M,
I’m sorry you’re experiencing this. It sounds like Personal Vault continues to work normally on your tablet and iPhone, but on your MacBook, it does not open after sign-in, even after testing several browsers, clearing browser data, restarting the Mac, and removing trusted devices.
I found multiple recent reports describing very similar Personal Vault problems on Mac. Some people could still access the Vault on mobile, while the issue continued in different browsers or even on another computer.
At this time, unfortunately, there does not appear to be one confirmed fix that works for everyone. Some affected users have resolved the issue by updating macOS, resetting their Mac user profile, or removing and then reconfiguring their Microsoft account verification methods, such as Microsoft Authenticator, email, and SMS (if you decide to try this, make sure you still have access to the account and have at least one working recovery method before removing or changing any security information, otherwise you could temporarily lose access to the account).
You can check the following threads about the same issue to see whether any of the suggested solutions are helpful in your case:
No longer able to access my Personal Vault on my MacBook Air
Help! No longer able to access my Personal Vault on my MacBook
...
I also suggest submitting the issue through the OneDrive Feedback Portal so the relevant product team can investigate further. You can search for an existing report first so you can vote or comment on it instead of creating a duplicate.
Please note that this is a user-to-user support forum. Moderators and contributors, including external Microsoft employees, cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas.
Hopefully this behavior will be sorted out soon. Thank you so much for your patience!
Best regards.