Simple way to check, try ripping to ISO using ImgBurn or something. Or heck, just copy ‘/BDMV/STREAM/00055.m2ts’ to hard drive using Windows Explorer or something. If either fails, your disc has a problem.
Apparently, Avengers: Endgame has already sold 2.78 million Blu-ray copies in the US within the first 3 weeks. How many of those are 4K, I have no idea. However, with how many they manufacture, some failures are inevitable.