I am scratching my head when doing HTTP setup on the domain that it is only Android gave an error as above title. It turn out, the solution is quite simple.
Open the Nginx configuration, and add these below lines
ssl_certificate /etc/letsencrypt/live/domain.com/fullchain.pem; ssl_certificate_key /etc/letsencrypt/live/domain.com/privkey.pem; ssl_trusted_certificate /etc/letsencrypt/live/domain.com/chain.pem;
ssl_trusted_certificate is mandatory.