When I turn the layer off, artifacts remain.
Bug reports
It’s probably more of a limitation than a bug.
If you Trim/Split or Boolean on a layer, the layer offset won’t magically snap on the Boolean intersection.
Same for dyntopo or voxel remesh, layers are kept but quality will degrade.
You can try doing the operation with the layers off (artefact will appear when you re-activate the layer but maybe it’ll be better)