Video freezes during playback, sound continues

Hi all,Installed a Ring Pro on Saturday - it went well, live video works fine, can communicate well with somebody pressing the button (in tests anyway).Sunday we hosted a BBQ & the notifications worked well enought to know my guests were arriving while I was in the back yard.Monday morning I'm noticing playing back videos, intermittantly they'll "freeze". Theres still sound, the scrub bar moves, but the video locks & then jumps ahead.Signal strength is -75, firmware reports to be the latest. Doesn't seem to matter if I view videos from the iOS app, or using windows & the web page.What am I missing?Thanks!