It was mostly turnovers that got them in trouble. They didn't notice is but they already got 17 turnovers before they finish the game while on the other hand the Bucks protected the ball so well they only had 5. Defense is almost identical. 9 blocks for the Suns led by Jae Crowder with 3 steals and 11 steals for the Bucks.
It just means CP3 is not keeping the ball protected if their turnover is higher than their past games. If Suns want to win another game it's just CP3 they needed to be back on high end performance.
Suns are lucky they got Booker going, I'm not sure if Suns can still win a home game in game 5, it's a very critical game for them as the pressure is already on them. If you look at the Bucks scoring, they are improving but on the Suns they are not, especially on Ayton who is not anymore producing points.