Since a while I have a problem accessing odoo

When I type my.domain then an infinite loop starts redirecting to web/login

At the end the browser throws error (too many redirects) and in the address bar I see very long: https://my.domain/web/login?redirect=https://my.domain/web/login?redirect=https://my.domain/web/login?redirect=https://my.domain/web/login?.......

if I type https://my.domain/web or any other path after the main domain then it redirects correctly to the login page

If I delete the session cookie then also it goes correctly to the login page

Once I log in then the problem does not occur unless I wait some hours and try again typing only the main domain

Cannot figure out where does this problem come from. Where does this parameter (?redirect=https....) gets added?

Could it be NGINX mis-configuration?

I have updated a couple of times in the last month to the nightly release but apart from that cannot remember doing changes to the system