I had the same issue ( also happened to me when I added external url in the odoo Website, the redirections didn't work well )

Modify the Odoo Configuration File: 
Ensure that your Odoo configuration allows cross-origin requests. 
Open your Odoo configuration file (usually located at /etc/odoo/odoo.conf).

Add or update the proxy_mode parameter to True:

proxy_mode = True

 then restart odoo : 

sudo systemctl restart odoo

and it should be working, if not then add the proxy_header configuration and allow_cors headers in your nginx , restart nginx and it should be working.