XR1000v2 with fibre ISP 4th Utility (UK) - Icotera i5205-00 bridge device issues

[VJ4YK5]

Hi all,

I was hoping someone may be able to help me. I've been hitting a brick wall for about 12 months with my ISP 4th Utility (they are truly one of the worst fibre providers out there for a number of reasons which I won't go in to).

In a nutshell they provided me with an Icotera i5205-00 bridge device in November 2023, this feeds the fibre connection to my XR1000v2. When I first got it I punched in the supplied PPPoE details in to my router, successfully connected and had no issues with it until June 2025. Since then I've had intermittent connection drops, where the fibre light on the bridge device flashes and the internet light on the router goes red. Sometimes it comes back up on its own, sometimes it goes off again quickly, sometimes it's just one drop. There's no real pattern to it to be entirely honest. 4th Utility don't want to know and just end up telling me to go to my router manufacturer, so here I am fresh off of an extremely frustrating 2 hour 10 minute phone call with them.

They originally supplied me with a Dasan H660GM GPON ONT router. It's ugly, the antennas are at ridiculous angles and I don't want it on my wall. As part of the troubleshooting I've been doing I left the Dasan in bridge mode connected to my XR1000v2 for a week and experienced no connection drops. In my opinion this identified the issue being with the bridge device, but they're refusing to send me a replacement and stating that the logs on their end indicate that the device is fine and it's a problem with the credentials which must be my 3rd party router's configuration (or something along those lines, I was so beyond frustrated that it's slightly difficult to recall). While on hold I checked this forum and thought it could possibly be related to the VLAN ID, I had to almost beg the person on the phone to check if there was one as he was outright refusing at first but he eventually stated that his senior said there is no tag.

Can anyone suggest anything related to the XR1000v2 that could be causing this? The bridge device has no GUI or ability to be configured, and when it's connected to the XR1000v2 via the WAN/Internet port the only thing I have configured is the PPPoE credentials (see screenshot). When I have the Dasan H660GM connected instead I do not change any config in the XR1000v2 but I do configure the Dasan in to bridge mode on WAN0 with Tag 201 (see screenshot) which seems to work fine despite the ISP stating there's no tag (I also do not know if this is correctly set but, it works?).

The only thing I can think of that's different from when I first started using the bridge device to now is that years ago the PPPoE credentials had a different username and password depending on whether you were using the Dasan router or the Icotera bridge device. They've since changed that and now it's one username and password regardless of which device you use. I have no idea if that's important or even relevant but I thought it was worth mentioning.

Unfortunately I live in a block of flats and I don't have the option to switch to a better provider as 4th Utility installed their lines here themselves, every day I wish CityFibre had instead.

Any help or guidance would be much appreciated!