If there is the option to do skip level or 1:1 with PO's manager and your company provides a safe environment to do so, let this be know in a polite and respect

If there is the option to do skip level or 1:1 with PO's manager and your company provides a safe environment to do so, let this be know in a polite and respectful way highlighting the PO's good attributes following that up with the endless loop habit which is a time sink for all. PO's manager will then take care of it in his 1:1 with the PO. Otherwise, if you are remote and not required to be on video, browse HN during his loops ;-).