I’ve had similar experiences with it telling me to call functions of third party libs that don’t exist. When you tell it “That function X does not exist” it says “I’m sorry, your right function X does not exist on library A. here is another example using function Y” then function Y doesn’t exist either.

I have found it useful in a limited scope, but I have found co-pilot to be much more of a daily time saver.

I agree, my regex experience was not great.

If you are going to use Visual Studio I would highly recommend getting the resharper plug-in or start using Rider as you IDE. Having good tooling like this will help you see the possible null reference errors before you even finish writing your code.