Bitdefender Box 2 - Can't use T3200M Bridge Mode?

[wireless]

I have had for a few years a Bitdefender Box 2 (basically a router / firewall to protect my IoT devices) attached to my TELUS T3200M without issues. To be safe ( I assumed); I have by Optik TV boxes attached directly to the LAN jacks on the T3200M (and using their own network). I put the T3200M into 'bridge mode' and attached the Bitdefender box to that 'bridge' port; no problems since purchasing the device a few years ago with this configuration. This includes switch from TELUS copper to fibre optic last year.

Early on July 15, my internet went down for no apparent reason. I contacted TELUS and was told the device (was Bitdefender Box 2) using bridge mode was the problem as it was acquiring too many IP addresses. Strange how after years this is suddenly a problem. Does anyone know more about 'bridge mode'? I assumed only one IP would be used by the T3200M and everything else attached would be via / behind that IP. Additionally, over the last few days since the initial problem; when the Bitdefender Box 2 was using 'bridge mode' on the T3200M it occasionally appeared to cause the 'FAIL' light on the TELUS provided Nokia Optical Network Terminal (ONT) to come on and all of my devices (Optik TV, internet) to fail. Removing the Bitdefender Box 2 resolved the issue.

As a workaround, I have turned off Bridge mode and the Bitdefender is now in a DMZ (outside the T3200M firewall) but, that has created some minor issues. Regarding DMZ mode, what setting should be used with the 'DMZ Timer' so that the device (Bitdefender Box 2) will always be in the DMZ?


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