ARSession stops outputting frames after some time when using .personSegmentation on 15.4 RC

session(_: ARSession, didUpdate frame: ARFrame) stops being called after a minute or so, with less and less frames returned per second until then. This only happens on 15.4 beta (and now RC). We've tracked this down to the personSegmentation frame semantic; the issue does not occur if we don't use this. Has anyone else seen this issue?