I watched towards the end of the match and Sinner, for some odd reason, can't quite seem hit the big serves. He would occasionally hit good 125 mph t-serves, but he was content hitting those 115 to 117 mph first serves. Then, in the 2nd serves, he was hitting under 90 mph and sometimes 77 mph. I do not think he has the yips on the serve, but as tall as he is, I do not know if he can't technically hit bigger serves or he is conservative on hitting bigger serves.
Also, those drop shots, please save those when you are ahead of the match and not during those tight, pivotal moments.
With that being said, I am impressed and proud on how mentally strong Sinner in these past three matches (including his last match at IW). Clearly, he is not playing his best tennis (I have feeling he is still feeling the effects of his illness he got after AO).