There have been officials that have either hinted at or outright said there is match manipulation (and at least one who said match fixing, full stop) in the premier league. But, shortly after doing so, they almost always go very quiet. Some retract their statements and others are shuffled off to far flung roles where they are out of the public eye whilst the controversy blows over.
The FA, League, and PGMOL have quite a lot of legal and financial power. It’s a similar power wielded but UEFA and FIFA, two organisation known the world over for saintly and virtuous operations.
There are many instances of corruption taking decades to expose, for the simple reason that people can be kept silent through coercion, threat, and brute force.
It is very telling that every time a highly suspect, controversial incident like the one last night where the referee told linesmen to raise his flag (knowing that the potential offside occurred in one of the blindsides of the stadium so VAR would not be able to overrule the decision), there is only a cursory explanation provided and then the established media and league/FA talking heads move on as if there is nothing more to be scrutinised.