thank you, it’s all ok now
i’ve made only a quick test, for me now it’s working with the correct cert on reverse proxy and not with others
i’ll do some other test
note: on nexcloud side i had a warning:
There are some warnings regarding your setup.
The reverse proxy header configuration is incorrect, or you are accessing Nextcloud from a trusted proxy. If not, this is a security issue and can allow an attacker to spoof their IP address as visible to the Nextcloud. Further information can be found in the documentation ↗.
solved adding the wan ip of nethsec as trusted_proxies in config.php
Thanks again 