Step 1:

Undo 5 screws with T4 Screw driver.

Step 2:

Open on the side as photo shown below. You might need to apply small force on the outer case. Access by gripping one side of the module slot.
[Beware! There are flex cable connected on the fixed end!!!] Do it slow and steady.

Step 3:

Where the flex cable located. No need to disconnect the flex cable for this repair.

Step 4:

Find your loose encoder and apply force on the other side while applying superglue, so it sit flush as how it should be. Apply glue where the screwdriver are indicated(very small drop does the job) and another drop at diagonal. You can confirm by moving the loosened encoder to double check where to apply.
[Beware!!! DO NOT apply glue on the ball bearing itself! You will break the encoder]
Apply force on the encoder and wait for the glue to dry. And reassemble the unit in reverse steps.

Alternative solution: Unmount the dial from the unit. Then find a very thin tape. cut a very small piece about 4mm x 5mm, and stick it on the contact cylinder and mount it back

[Disclaimer!!] This may void your warranty with TE. And I don’t hold any responsibility with your device. Find the right tool and do at your own risk.