Most likely regulator and or clips. Buy a regulator/motor assembly and the clips and replace everything. That should guarantee the longest possible cure. Having said that I had the new clips fail two weeks after a complete replacement.
Much rather have the old fashioned heavy door mech that lasted forever instead of these flimsy wire, pulleys and plastic clip junk modern vehicle offer.

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2021 X5 xDrive40i
2015 X5 xDrive35i MSport
(Traded) 2013 X5 xDrive35i