11ac wifi extender 1200 - won’t work with switch set to 5GHz

[Longline]

I’m connecting this BT wifi extender to a BT Smart Hub 2.  It works beautifully with the extender switch set to 2.4GHz.  But with the switch set to 5GHz, whichever method I use to connect to the router (WPS or manual), any device which connects to the ‘EXT2’ or ‘EXT5’ versions of my SSID simply cannot access the internet.  

Any ideas?  Thanks!

[Keith_Beddoe]

@Longline 

The extender only connects to the home hub at 2.4Ghz, it then generates it own 2.4 and 5GHz signals.

[Longline]

Thanks for that idea, but it’s not actually the case.  Yes, it does generate its own 2.4 and 5GHz broadcast signals, but it can also (and separately) connect to the router at either 2.4GHz or 5GHz depending on the switch setting on the top of the extender.  That is subject to the router also being dual band of course, and in my case (BT Smart Hub 2) that IS indeed the case.

Any more thoughts folks?

[Keith_Beddoe]

In that case it would be best to leave the switch at 2.4GHz, as it says in the user guide that your extender would need to be closer to the router.

https://shop.bt.com/content/uni2/documentation/b15p/11ac_dual-band_wi-fi_extender_1200_user_guide.pd...

Wireless extenders are never going to perform as well, as separate wireless hotspots, as they rely on repeating an existing wireless signal, and this reduces throughput.

[Les-Gibson]

The 2.4GHz / 5 GHz switch determines which carrier the extender uses to connect to your hub, if you can't get an internet connection with the 5GHz carrier selected then it could be that the hub and extender are too far apart to get a decent connection.

What colour are the lights on the extender when you are unable to connect?

[Longline]

Good thinking - thanks - but even with the switch at 5GHz the lights indicate either “Too close” or “A little too close”.  So it doesn’t seem like the separation is the issue.  

[Les-Gibson]

Do you have Sky Q?

Sky Q uses 5GHz channel 36, my thinking is that perhaps your extender is clashing with it by trying to use the same channel ???     

[Longline]

Nope,  no Sky.  Just two iPhones and a (switched off) laptop on 5GHz.  Plus one “unknown” (how can you identify a device from its MAC address alone?).  

[Les-Gibson]

---

@Longlinewrote:

Nope,  no Sky.  Just two iPhones and a (switched off) laptop on 5GHz.  Plus one “unknown” (how can you identify a device from its MAC address alone?).  

---

I suspect that you have just answered your question.

iphones from iOS14 onward use MAC randomisation for security, in other words they generate a random MAC, I suspect that one of those is your unknown Device.

Enter the number here and if it comes back as unrecognised that that is very likely the answer.