Selling my current lease

I’m in a lease of a 2017 BMW 440i GC, 30k miles. I’m on a 3 month extension and possibly looking at selling it. Shift is coming tomorrow to see the car but gave me an online quote which gives me $3k equity. Carmax’s quote gave me $2k equity, however when I ran the info through Vroom, their offer gave me $5500 equity. So I posted all my info including license and reg pictures, last minute before setting up a time for appraisal, they call me and say as of September 9th(maybe August 9th) they don’t buy BMW leases. Anyone experienced that in the past with them?!?!?
By the way Carvana gave me the lowest quote.