I'm looking for reproduction steps, it is inconsistent when and where this happens. Larger pre existing graphs don't have this problem while smaller newly created graphs will. It appears that making a graph more complicated can sometimes fix this issue.

Editor is 2018.2, happens in both master and HDMasterMerge.

Here is an example of this in master:
draggingmaster

Another:

Spheres inside nodes can expand, typically the node UI extends downwards as long with the UI input/output circles