Cox won’t update modem firmware

@Darkatt​  Agreed, but DannyS already verified that.  OP's issue is he has a user-owned modem with faulty firmware.  Cox won't do a rollback to the stable version they currently certify because their policy is not to support user-owned modems.  Cox controls the network so Netgear can't push out an update.  OP is forced to wait for Cox to test, certify and push out Netgear's latest firmware release, whenever that will be.  (It was probably created to fix the fault with OP's version).  But since Cox's current certified version is prior to OP's faulty one, that probably won't happen anytime soon.  Hopefully, Cox will include user-owned modems if they eventually push out a new version of the manufacturer's firmware.

@robj067   You probably should just buy a different, approved modem or lease one from Cox.  The only way I see for you to get your modem's firmware updated would be if Cox eventually gets around to it.  For it to be successful, you'd have to be connected while they're doing the maintenance.  But you won't know when it's going to be done and if your modem isn't stable enough to use it, you have a logistical issue.

I guess the moral of this story is "Buy your own modem at your own risk."  Cox won't help if there's an issue.  If you do buy your own modem, make sure it’s a brand on Cox’s approved modem list and it’s running a firmware version that Cox has already certified.  Cox still won’t troubleshoot or update the firmware because it will be a customer‑owned device.  But using a certified modem should reduce the chances of problems occurring.

Actually, Cox's Docsys Engineering will auto update ANY modem, Cox or 3rd party to the latest Cox Approved firmware automatically. I worked with them for many years when I was employed by Cox, and even beta tested firmwares with them. Got a free modem out of it, after they bricked my Netgear 6300 MANY years ago, LOL.  But they WILL support 3rd party modems, and they do auto update with the latest approved firmware. 

@Darkatt​ Good.  If that's still Cox's policy, OP could at least receive an update the next time Cox pushes out firmware for his type of modem, when and if that ever happens.  Is the auto update you mentioned only done after Cox has certified a firmware version, to update all applicable modems connected when the update is performed?  Is there any other, periodic or unscheduled process to update modems that don't have certified firmware?  (His faulty modem would have to be connected when Cox auto updates and he has no way to know when it's going to be done).  It appears Cox only does the one-time update after each certification.  If that's the case, OP still has to wait for Cox to test, certify and push out the next auto update.  Another factor to consider is that OP has a later firmware version than what Cox has certified.  There's no evidence Cox does any other type of auto update, but even if they do, they wouldn’t push a firmware version older than what he has.  For OP's issue to be resolved, he must continue using his modem with the faulty firmware until Cox pushes out a later firmware version.