It might be an issue with concentricity. If the nozzle is not perfectly centered it creates a step that the filament can snag on. It can then cause the already softened filament to bunch up during deretraction forming a plug in the heat break. I had this issue with cheap nozzles. Everything starts fine and after a few layers it all stops for apparently no reason. Cranking up the heat makes it better for a bit, before making it worse