Thanks for sharing, you might want to check for any other devices near the modem that could be making that beeping sound. I pulled up your account to check which modem you have, and the HT2000w model you have does not have any speakers to make beeping noises. There isn't anything that should make any audible sounds in your modem.
I've also checked your diagnostics and all appears to be working normally. I highly suggest checking for nearby devices if you hear the beeping again.
Good morning snoopy2,
I hope you found the source of that mysterious beeping. I'll go ahead and close this thread out, if you have any other concerns, drop by! Have a great weekend!