When did joshuas prime end ?

Round 9 of usyk 1, had usyk on the back foot and somewhat troubled in that round. Round ten usyk came back out full of gusto and there ended Joshua's prime.

 

It hasn’t started, it’s still yet to come…

 

When he beat Gary Cornish in the legendary battle of Britain.

 

In my opinion, his prime was until the first fight with Ruiz Jr., until this fight he seemed super confident in his abilities and he went out to knock out, and he fought against whoever stood in front of him. Then he changed his aggressive style for a confident and hesitant style and he seemed afraid in the rest of his fights, he was never the same.
He lost his confidence

 

Wlad cracked the glass, Ruiz shattered it, Usyk picked up the pieces and Dubois threw them in the bin.

I think it started with Wlad. AJ said he never wanted to be in a fight like that again. Wlad imo was the first guy that made AJ see just how badly he could get hurt in there, which shook his confidence.