Hi, yes there are some compatibility issues with NodeGraphAssistant. I have suggested the fix here if you’d like to implement it on your side: Issue with Alt+MiddleClick (break pin) and AutoSizeComments graph node · Issue #28 · pdlogingithub/UE4-Node-Graph-Assistant · GitHub
However I believe the bug where you can’t move a node inside a comment is an issue with the engine. This is related to the sort depth of the nodes on the graph and occurs even in the default comment nodes.
You can compile the graph and it should recalculate the sort depth correctly. Or you can try enabling the experimental setting EnableFixForSortDepthIssue in the ASC settings. This refreshes the sort depth any time you add / remove a node from a comment.