Artifice wrote:
I finally found the problem, it turned out to be "Enable Strict Security Firewall" on the router.

I have never had issue with this setting in the past. If I disable it then i can login to Disney on all devices and then enable it again.

I'm glad you're back on air - but, for me, it's another one of those issues, without a satisfactory explanation ...

The manual says

For the sake of security, the router will execute strict security checking for data transmission. Such feature is enabled in default. All the packets, while transmitting through Vigor router, will be filtered by firewall. If the firewall system (e.g., content filter server) does not make any response (pass or block) for these packets, then the router’s firewall will block the packets directly.

What does that even mean? It could presumably only apply to broadcast/multicast messages ... because otherwise the absence of a NAT mapping would block traffic anyway. (and I've never had to add Firewall Rules for mappings created by uPnP)
I suppose 'multicast messages' and 'Video playback' are sometimes found in the same sentence - but it doesn't seem directly related to not receiving the login web page :?

I will add it to the list of life's great mysteries (along with "why are people so interested in Meghan Markle"? )

Webinar - Firewall and its Application Part 1: https://youtu.be/P-BHhGO7tKk?t=840 (Draytek Aust NZ)

At 14:02, the man says: (I paraphrase :wink: ) - that it's there in case the external Content Filter services don't respond; the Vigor will default to "Block". I suppose that is what the manual says, but I needed to hear it spoken out loud :lol:

So what happens if you don't make any use of such services?...
...from the OP's experience, it seems like it does some kind of checking of them regardless...