I've had this problem.
The problem is caused by a strong spring on the handle assembly itself breaking its 'holding' cage.
Not that easy to fix.
Here are the notes from my service file I made when I fixed this problem.
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Opening door something 'pinged' and the handle spring resistance
became less and handle would not fully return unless pressed down.
Stripped door down (see eLearn for trim, door handle switches removal etc.).
Unclipped glass and propped window high with top rear window edge actually outside of the window frame to allow access to back of door handle.
Removed inner frame assembly including disconnection of door jam electrical connection.
Followed eLearn to remove outer door handle.
Fully removed VERY STORNG handle spring which had both worn the handle platic
and broken part of the 'cage' chamber.
NOTE! When refitting handle you will find that the outside handle will be in the
up position. You have to release the 'pawl' by manually fully closing
the lock. Then the handle will drop and be lifted down by the inner lock mechanism.
Door handle feel / action actually alot better. Softer and still returns.
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Sorry the notes are a little cryptic. They read ok after doing the job but that was over two years ago.
An extra bit that I recall is. Take a very very careful look at the inside of the handle and how it is connected to the rest of the lock mechanism before proceeding. To actually remove the handle assembly there is a flat fishplate that slides in to retain the assemby.
Good luck.
Nick