When I stand up when riding in the power mode, the crank kinda slips and makes a clunking sound. The bike doesn’t appear to adjust to the standing up position. It works well in the seated position. Anyone else having a similar problem?

Did you get to the bottom of this issue? I think my new Neo Bike Plus is similar. You have to pedal super smoothly to avoid a clunk when the crank re-engages with the power delivery. Im currently using MTB flat pedals and shoes which is not likely to help

I had the same issue, I had a loose belt tension pulley,  the threaded bottom bracket for the crankset was also loose, and the left pinch bolt for the crank was loose. Tightened those all up and my knocking sound is gone now

What procedure did you use to tighten up loose belt tension pulley? The loose threaded bottom bracket for the crankset? And the left pinch bolt? Do you have the torque setting?  Is there a video or instructions on how to complete these adjustments? Thanks

The last pinch bolt torque value is listed on other threads here. 

I couldn't get any torque values from Garmin support, they didn't seem to understand what I was asking for.

For the belt tension pulley  , I tightened it until seemed snug but wasn't binding or dragging. ( just spin the cranks and you'll see what I mean)  the  threaded bottom bracket on the right  was VERY loose and I just hand tightened it as much as possible. if i were to do it properly I would need the exact bottom bracket tool.

You need to undo the pinch bolt on the crank and then get the belt tension tool from Garmin to loosen the belt then pull the crank pulley out. Then you'll get access to 1 half of the bottom bracket. 

To get access to this stuff you need to remove the cover of the unit with  torx bit.

I think most of these problems are probably just bad quality control on garmins part and they're not torquing bolts to spec when putting them together.