Experience same once with my X5 but when it engaged almost after a second and half it kinda "jumped", the following day it never did, thats almost a week now just crossed my fingers, I had similar issue with Lexus (Automatic) - it was 'delaying' into reverse after 3 days it just couldnt go into reverse!.

After assessment it was noticed that trans oil was too little and affected clutch! Thats why I said I crossed my fingers with my X - these machines can really make one pay thru the nose!

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