This is somewhat normal for FDM 3D printing. It’s a known behavior of filament in its molten state on the interior walls. As the nozzle goes around, it’s always at a tangent to previously laid filament, and can have the effect of pulling just-laid filament off of its bedding into the previous layer.

It’s one of those things that to fully understand I’d have to find one of the dissertations one of the community members did.