Hi, Mike from Fusion3's support team here Happy to help.

This kind of looks like the actual polygons of your model? We've seen a few people come to us with similar issues and what it ends up being a good portion of the time is that the F400's print quality is accurate enough that you actually can SEE some of the polygons in a model. I'd love for you to send us a .factory file of this part from Simplify3D (File>Save Factory File in S3D) and email it to us at support, to confirm.

This model here has a lot of polygons and is exported from CAD with a high detail setting - and you can see that it doesn't have any of these ringing issues. Printed on "standard" quality at stock speeds: https://i.imgur.com/Jz2qFLq.png

If you turn on "wireframe" mode in Simplify3D, and the "ringing" seems to correspond to where the polygons are in the model, this is the case.

However, We'd really prefer if you emailed our support team for this sort of stuff - it allows us to dive deeper into any issues and have a record of what's been tried to fix it as well. The contact info for support is on the white sticker under your power plug on the right side of the machine.