Could be the problem with Lets Encrypt.
https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/
Search for a solution: https://help.nextcloud.com/search?q=DST%20Root%20CA%20X3
I think you must delete one CA certificate.
Could be the problem with Lets Encrypt.
https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/
Search for a solution: https://help.nextcloud.com/search?q=DST%20Root%20CA%20X3
I think you must delete one CA certificate.