GnuTLS recv error

I’m getting this error on System Notices, it seems that gitea cannot update external repositories:

fatal: unable to access 'https://github.com/(...)': GnuTLS recv error (-110): The TLS connection was non-properly terminated.
error: Could not fetch origin

The system uses a proxy (with inspection) to connect to the internet, the proxy is set through env.
Any ideas on how to debug this issue?