They seem to be the same person.

I tried to suggest an alias, but it says it's already an alias (but not to each other?)

There is a pending alias for these tags in forum #279037.

if your alias suggestion doesn't work, the easiest thing to do is search for your tag on this page
https://e621.net/tag_alias

as it most of the time has a forum link, there you can make updated suggestions to said alias an what not.