Saw this theory on Twitter: Dexter Lumis is targeting Miz not because Ciampa but to get him to wake up/renounce evil and prepare him for the impending return of Bray “The Fiend” Wyatt so that Miz can stop Bray before he resumes his reign of terror.
Miz was one of the first victims of the Fiend and the dropped plot point we had with regards to The Fiend being able to use his gloved hands to invert wrestlers heel/face status (with Bliss, Miz, and IIRC Rollins all turning heel after the Fiend got a hold of them while Daniel Bryan got turned from evil to good by the Fiend).
It explains why Dexter vanished (he sensed Bray's return and has been plotting to stop him/find someone who could stop him if he can't do it himself). And why he's keeping Indi at a distance: he doesn't want the Fiend to get a hold of her or invert her evil to make Indi his new sidekick in evil like Bliss was. Same with Gargano and Theory.
Jesse
You spend way too much time thinking about Dexter Lumis.