It was borderline sinister.
There was loads of crowd noise, City on top, noise gone. Halftime, all the noise kicks back in, second half, crowd noise again, City on top, suddenly, gone. Totally gone, like David Coleman from Mexico in 1970, with one mic.
Imo, it's because they have noise gates on the crowd mics & someone has changed the threshold they are operating at, so effectively most of the surround system is shut off, until there is an announcement blasting out over the PA, then the gates open & you hear it come out of the speakers.
No reason & probabably no facility in the software/hardware, for the gates to change themselves like that. Someone in a truck, has decided to alter it.