He might have plenty of excuses and I can’t imagine how he’s been affected by the racism and unacceptable social media behaviour, but it is quite a long time since he sustained anything like a run of form.
I don’t think he’s justifying his place in the team at all.
Presumably playing him through this poor patch is part of the plan to get him firing again, but it’s not working so far.
I’d try alternating him with Cavani, as in strictly selecting them in alternate matches, telling them up front that that is the policy to keep both fresh and see if it does anything for his confidence.