When using RSO with Editor Extensions personal Lab, biter and ore will be generated on this Surface. See https://github.com/raiguard/EditorExtensions/issues/103 . My first assumption that it is related to the new EE version was just a coincidence. I didn't use the Personal Lab enough to see the biter on the old version.

I thought that RSO should be using map settings from surface it generates on but it would seem something doesn't work correctly there.
I might take a look but not sure when - alternatively there is a remote interface in RSO to add ignored surface and RSO won't run on it then. That would need to be added in EE so it's up to author of it.