Unable to properly setup openvpn connection with network manager

Hi all, I’m trying to set up my laptop with endeavouros (it’s machine I use for work) and I have some trouble in setting up the vpn connection.
I imported the openvpn config file with network manager and I’m able to open the connection and reach the remote ips, the problem is that when the vpn is on some sites (es. forum.endeavouros.com) are unreachable.
If i open the vpn using the command
sudo openvpn myvpn.ovpn
all works as expected and everything is fine
if I open the vpn connection using
nmcli connection up myvpn --ask
(myvpn is the connection that nm created importing the vpn file) a lot of sites became unreachable (and the connection is very slow).
Can anyone help me in diagnosing the problem?