Finally found some time to take a photo of my rear tyre. The tyre is the Micheline Pro tubless. The tyre is separating form the sidewall. I think it might have to do with the rubber compounds not getting along anymore.
Tyre still holds air and isn't giving my trouble so I am not bothering to replace it for the moment. I am keeping my eye on the tyre though. 5,600+ km on the tyre so I figure I am doing ok.