We identifed this issue in both 5.3.0 and 5.4.0. It is still ocurring.
I have now completed the necessary Polycom certifications and we are able to open tickets directly, so this has been opened as SR # 1-2019790401.
I am currently attempting to collect the necessary information (packet captures, syslog, phone config etc) for further investigation. Our latest update from the engineer the ticket has been assigned to is that the cause of this issue has not been isolated yet, that it is still ocurring in 5.4.1, and the suggested workaround is to disable the hold reminder beep.
