Linn Karik CD player : Drawer does not eject

I have a Linn stereo system for many years which I adore.
I use Linn Karik CD player for 20 years now serving as a transport.
In recent years I experience a problem that has become more and more acute : Drawer does not eject.
There is a high-end stereo technician in my area who is a mechanical guru. He checked my Karik and performed the following:

1. Replaced all rubber transmission belts (not original ones though but ones at similar size).
2. Lubricated all axles and gear parts.
3. Y axis movement of the drawer works properly.
4. Ejection motor seems to work.

Every time he performed the procedure mentioned above, the problem was fixed for a few days but then it would come back.

Here is video of the ejection process of the same CD (not mine) : https://www.youtube.com/watch?v=R4IEpUEnlJc

Any thoughts ?