Email preview page giving 403 error

Your software
My Mautic version is: 3.3.3
My PHP version is: 7.3
My Database type and version is:
MariaDB
Your problem
My problem is:

If anyone other than my logged in admin account accesses /email/preview/* it gives a 403 error.

I can see them because I guess I’m logged in to admin. Even if i go to another browser and access the url, it gives a 403.

These errors are showing in the log:
none

Steps I have tried to fix the problem:
Tried turning off cors, add the domain to trusted sites.