At some point late Thursday, Diddy got rid of every single IG post on his page -- wiping it completely clean without any explanation ... and that includes the video he posted where he addressed the brutal video of him beating his then-girlfriend.

The internet was rife with theories on what might've been behind the move -- but sources with direct knowledge have assured us there's nothing behind the move other than Puff wanting to reset his posts ... something we're told he's done in the past.

We're told Diddy wasn't taking a dig at Cassie either by getting rid of his apology -- which is evident in the fact that deleted all of his posts ... not just that one.

The way our sources put it ... Diddy's apology was seen around the world and got published/broadcast everywhere -- so everyone's seen it, and it exists forever. In terms of how feels ... we're told Diddy meant what he said in that clip, and that stands even today.

In other words ... him scrubbing his IG is in no way a swipe at his ex -- nor is it him downplaying the seriousness of his sitch. Plus ... our sources say he's done this before -- so this isn't out of the ordinary for him ... it's just magnified because of all the attention lately.

The last thing that's been relayed to us is the fact that this scrubbing was NOT a strategic move between him and his camp -- it was just a spontaneous thing, and it really bears no significance on the bigger picture of what's going on with him these days.

As you know ... Diddy is under a microscope -- the feds are investigating him, and he's facing multiple lawsuits with heinous allegations, which he's denied. Obviously, every little thing the guy does right now will be ultra-scrutinized ... especially a mass deletion like this.