When you click on a different profile (or use the up or down arrow keys to highlight different profiles), does the text colour for the name turn red?
Try hitting the Enter key, rather than clicking the Select button.

Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin 2\PlayerProfiles\<ProfileName>\Savegames' folder.
Try moving all your saves from your current profile to the Savegames folder for the new profile, then delete/move the current main profile. Alternately, move your current main profile somewhere else, start the game, create a new profile with the same name, exit and move the saves to the that new profile.