I had the exact same problem sewing potholders with a layer of batting, layer of Insul-Brright and up to 6 layers of fabric (binding the edges). My Baby Lock Soprano is a workhorse and it was clucking and skipping stitches.

The internet consensus was to use a bigger, heavier/stronger needle, like a 90 or larger. Nope. That made it worse

I ended up having the best luck with a smaller thinner needle - 70/10, and universal worked better than a sharp or microtek.

I think it's the Insul-Bright needing to be "parted" more so than "pierced". Having said that, I did not enjoy working with it.

I learned if a machine stalls over thick places then it cannot handle it. Not enough power to push the needle through no matter what size needle. I took a potholder layered like what you have and binding with me when I was deciding on a new machine. I was surprised at the many models would stall when adding the binding over a join or corner.
I will add I bought a Juki, it is powerful and in my price range.

This is so true. My older Bernina 180 sews anything. I stupidly assumed the new ones would be the same. I bought a 475 and it doesn't sew anything heavy. My 180 and my Juki are my go-to machines for heavy weight projects.

I have a Juki HZL dx5. I bought it a few months ago. Thank you.

Exactly. It made it worse for me too. Everyone said larger needle but the larger I got the worse the sound.

Is the Juki HZL dx5 an industrial model? I have the Juki TL 2010, it is industrial, straight stitch only.

No. It is a home model

I have the Juki 2200 QVP Mini (same as the 2010)