I've built the latest ApiClient version from source and released E2PL v220.127.116.11-beta which is now using this client instead of the NuGet package.
I haven't made any other changes and haven't had time to set up a VM with the latest version of the server, so I'm not sure if this actually fixes anything or not. It does seem to work with the old server version that I'm using for my own media. Anyone having the authentication issues could give this a try and with a bit of luck it'll work, assuming the new library uses the new authentication method in the background when talking to the server. If not, I'll get an install of the latest server going and look into it in more depth when I've next got a bit of time.
Thank you for your great work, I got it working.
Edited by angryblue, 09 December 2019 - 09:50 PM.