This can happen if you have enabled private browsing, or disabled third party cookies.
It can also happen if you are using some adblocking DNS provider on your network that is blocking some things on Persona... but frankly this is extremely unlikely.
Look at the browser settings, if Persona cannot store session data then it cannot sign you in. That is the essence of the problem, and also the solution.
This can happen if you have enabled private browsing, or disabled third party cookies.
It can also happen if you are using some adblocking DNS provider on your network that is blocking some things on Persona... but frankly this is extremely unlikely.
Look at the browser settings, if Persona cannot store session data then it cannot sign you in. That is the essence of the problem, and also the solution.