Replying on Geoguy180's behalf since he's away for the weekend and I was discussing the issue with him yesterday.

He doesn't know why there are two players, but his saved sessions use Geoguy181 with a capital in the name. It looks like almost all his achievements are on the capitalised name, however you can't view them as when you visit https://recursiontracker.com/player/<name> it isn't case sensitive. The lower-case name version only has very few achievements recorded and can probably be deleted.

Here's one of his saved sessions which also has the capital G: https://recursiontracker.com/?p=c&c=saved&id=30491