[yellow69z28rs]

I've owned a Tint and Acc store for 28 years. glasstintetc.com
My entire windshield is tinted with 50%, also on all my other GM vehicles.
Put lots of 50% on customers vehicles windshields regularly.
Never had this problem, they may have got it wet are dirty and or disconnected it in the course of the job.
Take it back to your tint installer and ask him to check it out.
But for sure 50% is not your problem.