1. Create a simple level sequence with a moving ball
2. Add it to Movie Render Queue and then add the Anti-Aliasing setting to the configuration.
3. Set the temporal sub-sample count to 8.
4. Render the Level Sequence. The resulting images should have a nice blur between them.
5. Under the "30fps dropdown" in Sequencer, enable "Lock to Display Rate". You may need to change the Clock Source to Platform (instead of Tick)
6. Render again. Inspect the resulting images, they're all stuttery.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-139967 in the post.