It sometimes happens that the Network Connection tool fails to remember the password for an OpenVPN connection. I had two OpenVPN connections configured, both with the setting `Store password for this user only (encrypted)` selected. For one of them the password was being remembered, but not for the other one. In the case where it doesn't work, it was enough to select `This password is not required`, Apply, select again `Store password for this user only (encrypted)`, and then the password is properly remembered.
Created attachment 114086 [details] The OpenVPN configuration that caused the bug in my case.
I'm seeing the exact same problem in plasma-nm 5.17.3, but I can't fix it by selecting "This password is not required" and then "Store ... (encrypted)". I can only choose to store it unencrypted and only then I see the pwd stored in the (system wide) conf under /etc/NetworkManager/system-connections
This is a bug in NetworkManager. Upstream bug: https://gitlab.freedesktop.org/NetworkManager/NetworkManager/issues/230