Are you playing the Classic version or Definitive Edition?
There is a known issue in the last version of Classic where he will not move to the Lady Vengeance when invited.
If that is not the case, if you create a new profile, exit, copy your last act 2 save over to the new profile and load it without mods, is Corbin still on the Lady Vengeance in act 3? Alternately, you could temporarily disable the mods in your current profile to test.
Please email supportdos2@larian.com with your latest act 2 save (or a Dropbox or Google drive link, etc); for the Definitive Edition, also include an act 3 save. In either case, include a list of non-Larian mods enabled and/or the modsettings.lsx file from your profile folder.
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin 2 Definitive Edition\PlayerProfiles\<ProfileName>\Savegames\Story' folder (without the 'Definitive Edition' part for D:OS Classic).
In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipped) Folder' (and similarly in OSX/Finder).
