Cannot import OPVN Files in Network Manager

[infidelus]

 * cinnamon-control-center version: 5.6.1
 * Distribution - (Mint 17.2, Arch, Fedora 25, etc...): Linux Mint 21.1
 * Graphics hardware *and* driver used: GeForce RTX 2070 - nvidia-driver-525
 * 32 or 64 bit: 64

Issue

It seems impossible now to import .opvn files into the LM network manager. These files all work using the openvpn terminal command. Originally queried on the LM forum.

Steps to reproduce

Open Network or Advanced Network Configuration
Click + and select (Network) Import from file or (Advanced Network Configuration) Import a saved VPN configuration
Locate a .opvn file to load
Receive error:

Error: the plugin does not support import capability

Expected behaviour

.opvn file should be loaded and only the required username/password should be necessary

Other information

I'm about 99% sure this worked on LM 20.

Sample file, renamed for upload purposes.
ath-001.txt