At the start of the season I'd have pointed to our system change not helping Mo, too much play going down the left, Mo being isolated on the right (as borne out by average position stats) and adjusting to life without Trent.
Next, I'd have said his form is way off, a big slump.
Now I'd say it's a funk, not something that will suddenly spark back into life. Slot has tried to let him play his way into form, it hasn't worked and because he is a selfish player (as most great goalscorers are) and doesn't track back (as most great goalscorers don't) then you can only justify carrying him if he is doing the business. He's not, so he needs time out of the side.
But all this sulking and passive aggressive social media stuff? That can get in the bin. Time out of the team is part and parcel of being a footballer, and you need to be professional about it (talk to Robbo or Gomez, hell even Darwin didn't behave like this). He needs to stop fucking about and start working harder at Kirkby. Not ready to write him off yet, but he needs to fucking grow up.