Xbox Series 360?

I have had every Xbox since the OG VCR. I have both the Series S and X. Every once and a blue moon while navigating the guide and clicking a game or the home screen it'll close and show the old xbox 360 guide closing. I haven't experienced this on my old gen xbox one consoles. It has happened more than once for me but everytime I try to look if anyone else has had this happen I get nothing. When I cast my YouTube to my xbox it labels it as "Xbox 360". Is Microsoft recycling old xboxs or the OS? Although this does happen more on my series S than the series X, it still happens. Curious if anyone else has had this happen or noticed this or even has a explanation.