So What's Going on With the Bills and Stefon Diggs?

The Buffalo Bills began their mandatory minicamp on Tuesday with glaring absence: star receiver Stefon Diggs. While Diggs not being there was a huge topic of conversation, no one is saying what the problem is. It apparently has nothing to do with money or a new contract, so we have no idea what it could be.
Bills head coach Sean McDermott said he was "very concerned" that Diggs wasn't there on Tuesday:
Stefon Diggs is NOT here at #Bills mandatory minicamp.
— Dan Fetes (@danfetes) June 13, 2023
Sean McDermott says he’s ‘very concerned’ but would not go anymore into his absence. #BillsMafia @BuffaloPlus
ESPN's Josina Anderson is reporting that Diggs' absence isn't about money:
2/2 I’m told the nature of the private talks is “not money-related,” though the heart of the matter wasn’t shared, at this time. While a team source said Diggs left prior to practice today after previous meetings, the expectation is he’s returning to the facility, per source. https://t.co/PO4xvQbtb7
— JosinaAnderson (@JosinaAnderson) June 13, 2023
Quarterback Josh Allen claimed that, as an organization, the Bills maybe needed to communicate better:
“Maybe as an organization we’re not communicating the best way.”
— Dan Fetes (@danfetes) June 13, 2023
-Josh Allen on Stefon Diggs #BillsMafia #Bills
Von Miller fully took Diggs' side in the matter -- whatever it is -- claiming he wouldn't be in Buffalo without the All-Pro wideout:
“I’m on Stef’s side… there’s wouldn’t be a Von Miller here in Buffalo without a Stefon Diggs.”
— Dan Fetes (@danfetes) June 13, 2023
-Von Miller #BillsMafia pic.twitter.com/vcZhmZ1oNG
Allen reiterated that he loves Diggs and that the organization is "working on some things" internally:
Bills QB Josh Allen on Stefon Diggs: "I know internally we're working on some things. Not football-related, but Stef, he's my guy. Excuse my ... I fucking love him. He's a brother of mine. This does not work, what we're doing here, without him."
— Albert Breer (@AlbertBreer) June 13, 2023
In summary, we've learned whatever is going on has McDermott concerned. We also know it isn't money-related, isn't football-related, his teammates love him and, according to Allen and Miller, Diggs wants to be there.
Trying to summarize the Stefon Diggs saga:
— Dan Fetes (@danfetes) June 13, 2023
-Diggs is in Buffalo.
-Was at the team facility this morning.
-Left.
-Sean McDermott is 'very concerned."
-Josh Allen says it's 'not football related.'
-Josh Allen: "I f----- love him" and has his back.
-Von Miller says it's 'not that…
So what, exactly, is going on here? No one seems to want to say why one of the NFL's best receivers is sitting out mandatory minicamp, when everyone in the organization seems to know the reason.
It doesn't sound like any clarity is coming from the folks in Buffalo any time soon.