Solution:
Ensure pedals are correctly installed by fully tightening against crank arm, then securing with lock nut.
See this FAQ for instructions on tightening. > https://echelonfit.zendesk.com/hc/en-us/articles/1500006302822-How-to-Fix-Knocking-Coming-from-the-Center-of-the-Connect-Bike
If knocking noise continues, your belt may need to be replaced.
If this is a case send in a clear video of the noise you are hearing to customer service.
The shroud will need to be off in the video so the belt can be observed.
It will need to be diagnosed by our agents to ensure the correct troubleshooting is done and or correct part is sent if need be. Make sure to provide your serial number to customer service.
(Video instructions down below for replacing a belt)
https://www.youtube.com/watch?v=jiz6RYaYyKM