Not receiving incoming calls using Digital Voice

[CaptainVideo]

I've had three recent occurrences of inability to receive incoming calls. Outgoing is not affected, and I have a dial tone.  Each time Support has run diagnostics and rebooted the fiberoptic connection, and sooner or later the problem goes away.

I have an appointment for a technician to check things out later this week, and, as of an hour ago the phones are working.

Any insights as to what may be the problem and what a long term solution might be would be very welcome.

Thanks