Netgear CM3000 lag and instability

I’ve been trying to get my modems firmware rolled back to the one previously used before V6.01.04, it’s a commonly reported problem and a fixed hasn’t been pushed yet. Xfinity chat support keeps telling me they can only get me their modem and that they don’t control firmware which is a blatant lie as Internet service providers are the ones solely pushing firmware updates. @Xfinity Support