Ok. Thanks for the comment. I will work with the previous version until the issues are fixed.

Update: Looking at the comments in https://forum.game4automation.com/en/communities/1/topics/356-error-in-opening-secure-channel-badencodinglimitsexceeded, I downloaded a previous version of the game4Automation in  https://game4automation.com/download/customers/, concretely the 2019 one.

This version works perfectly, and I can read/write OPCUA nodes in Unity (tested in Unity 2021.3.2f1 editor). However, it would be good to work with the latest game4automation library.  

I tried to communicate locally (localhost) with the same result.

The server I'm using is:

https://www.kepware.com/en-us/products/kepserverex/version-6/