Phone stuck on DHCP Discovery

[SebJenkins]

During the pandemic,we configured some telesales staff so that they could take MiTEL 5320e desk phones home...I believe they are using Teleworker licences and are connected to their routers over ethernet via a PoE injector.

All have been working absolutely fine for ages until suddenly one day last week, two of them, the phones don't boot beyond DHCP Discovery...and they just stay on that screen and get no further
All other users are unaffected

For these two users all other devices are getting IP addresses Ok from the router, including laptops, phones etc...just the Mitel 5320e phones cannot get past DHCP Discovery
It maybe conincidence but the two users affected have SKY routers. like I say has been working for months...until suddenly last week...these aren't the only users with SKY though..others with SKY continue to work OK
I was considering trying a different router for the purposes of testing but I know SKY are fussy about which 3rd party routers would work

Any ideas ?

Many thanks in advance!

[Dogbreath]

I have heard from a customer that Sky routers do not play well with MiNet. It's something to do with NAT, as they found by experimentation that sticking another router, also doing NAT, between the phone and the Sky router got it working. Yes, double-NATing it fixed it. I have not confirmed this myself.

[johnp]

Sounds like a cable issue and the phone is getting no receive. Never seen a teleworker not get an address unless the cabling was bad.