We have a dev environment where there are two sources for resolving names in people pickers. The spelling of the name gets corrected when you enter domain\user, but then it states there are no matches. When you click on the name two sources appear for the user (see image). We completed deleted the UPS and recreated it but are having the same problem. The incorrect one is the "STS De 2" item in the image. I am not sure where this is coming from. Any help is appreciated.
Also, I configured the USP and AD connections exactly the same as our prod environment, down to the users/groups selected for syncing. The prod environment does not have this problem
In case you can't make out the user in the picture, it is "domain-name\Domain Users"