Relying on mercenaries too much is always a bad idea. Let alone using mercenaries in what is basically your own territory.
They should have pulled the plug on Wagner a long time ago. When they started attacking Russian Army units around Bakhmut allegedly because they were withdrawing from their positions it should have been the final straw.
The Russian government intelligence services started Wagner because it provided them with a cover for plausible deniability for foreign military ops I think. But using mercenaries in a war right next door, and in such numbers, was a massive mistake. One of the reasons for the fall of Carthage was their excessive reliance on hired mercenaries, and there are other instances of that in history.
I think the Russian military command for the operational theater in Ukraine is in Rostov. So Wagner is probably trying to decapitate the military command as a first step for whatever stupid thing they want to do. Maybe they want to "punish" the military command like they did to those Russian Army units around Bakhmut. This is retarded and they need to be disarmed and broken down. There should be no space for alternative chains of military command.