This problem is common on the XF - The rotation mechanism has a failsafe plastic gear. I you force it, it snaps. Its a 7 to £12 item on Ebay and all you need is 1 torx screwdrriver and a set of plastic trim removal tools. How to change is on you tube - I changed mine in 30 mins.
I got mine at RimmerBros. https://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwjB67mfvZT4AhXggFAGHULjCJUYABAJGgJkZw&ae=2&ohost=www.google.com&cid=CAESauD2sFTJgGXDsmYoycJoSzLWvc_8InwWHqWbITg55nCNcrPc1QfLuALLWUlpIYyX1OpBtu_RJlqBJ2lxmkyGOraW25pTRoaGl-nXm4egFff_Tv1RnLNuicuHV1sxB3GYJK-Rn1n5wuolh3I&sig=AOD64_3_HtDoP3p6N8t8Q25o7C9KEDoxQQ&ctype=5&q=&ved=2ahUKEwj88rKfvZT4AhVREsAKHVycCd0Q9aACKAB6BAgBEEE&adurl=
