
Setting RigidbodyTimeline3D.isKinematic has no effect
As the title states, setting timeline.rigidbody.isKinematic doesn't seem to do anything. At least, it doesn't set the actual backing UnityEngine.Rigidbody property accordingly.
This seems contrary to the summary tag, which advises, "Use this property instead of Rigidbody.isKinematic, which will be overwritten by the physics timer at runtime."
This tripped me up for a while, so for my own project, I've just made the setter protected for now.
Answer

Argh, it seems like 90% of the bugs in the last 3 or 4 patch versions are all about these properties! :P
I get tired of fixing them and creating a new bug on the side.
I'll look into it once more, thanks for the report.

Hi Schazzwozzer,
I just noticed you're using version 2.2. Can you update to v.2.4.9 and tell me if the issue still occurs? I can't reproduce it here.
Cheers,
Lazlo

So... it's been several days since I've tinkered with this stuff... but when I reopened the test scene to check, my test Rigidbody did not actually seem to have my test script attached.
When I attached it, it functioned as you'd expected it to. Toggling Timeline's isKinematic did indeed make the rigidbody stop moving.
Oops.
So, it looks like this is just a PEBCAK situation. Sorry about wasting your time! I swear the issue seemed very real and convincing the other day.
Customer support service by UserEcho
Hi Schazzwozzer,
I just noticed you're using version 2.2. Can you update to v.2.4.9 and tell me if the issue still occurs? I can't reproduce it here.
Cheers,
Lazlo