First and foremost, look down at the front chainring as it rotates. Is it even, or is it wobbly? If its wobbly in any way you have an issue with either a bent chainring or something with the bottom bracket (could be as little as being a bit loose).
Looking at the Sondors factory photos on their web site, I would be willing to bet they did something very common among direct-to-consumer bikes: The chain is too short. So when you are on the big cog in back, the derailleur cage is pulled forward. The photo of the white bike shows exactly this. The fact that there is a really big chainring on the front exacerbates the issue. Plus the Step stays aren't all that long, and getting setup right all the more important. Lastly, Steps have been sold in large numbers that were factory seconds/returns at a discount. You could have one with an issue that did not get corrected when it went back out.
A narrow-wide ring is pretty much a no-brainer, although there is something to what
@sojourner says with regard to fixing the problem rather than papering over it. For a 1x drivetrain the method of determining chain length is different from the one used when you have multiple front chainrings.
For this MTB How To, we are going to be focusing on setting the correct chain length when installing a new mountain bike chain on a 1X drivetrain. Making sur...
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In short, when on the smallest rear cog, your chain should be long enough so the derailleur cage is just long enough to have tension on it. The cage is there to wrap excess chain. Its a common mistake to not put enough chain on so it can properly do its job. Here is a picture of a chain that has been properly adjusted with this in mind. Compare what you see here to what is typical with DIY builds and even low-cost factory builds.
hi gear. Cage points straight back but has enough tension on it that the rear/bottom pulley does not interfere with the front/top, and the chain is pulled taut.
Low gear. You can't make the chain any longer than what you did in setting it for hi gear, so the low gear takes care of itself and is what it is. In this case with a relatively small 32T cluster, the positioning is perfect with the top pulley being just a hair ahead of the bottom.
With big modern day clusters in the 46-50T range you can't help but have even a super long cage pull forward, but getting the low gear right keeps it reasonable. This one below is 50T... huge. But it still isn't too bad in the stretched-forward department
Compare your bike to this, and I bet you need to go get a new chain and put it on with more links.
