Extender only outputs 5GHz, can't connect to 2.4GHz

[Kabina]

I have myself an EX7000 wifi extender, I have it set up in a shed outside my home so i can have good internet access for myself and a handful of smart devices when out there.
When setting it up and connecting to my main router (provided by spectrum) I am told 2.4GHz has a 60% signal and 5GHz is getting about 35% which isn't great but should be enough for basic usage.
And it was for the first few months I've had this extender. In fact Ive been able to go on vacation and control devices on the go, stream videos and even play games at very low ping and good download/upload speeds.
These last few months however have been a chore. It started with 2.4GHz output on the extender starting to become unreliable, and now has just become downright useless. It broadcasts perfectly fine, full signal, and it's receiving a connection from the router, but nothing connects, every device gets stuck on connecting and either fails with no error message at all or "could not obtain up address", however anything connected by 5GHz works fine, and anything directly wired also works flawlessly.
I have tried every option in the extender. One-wifi on and off, smart connect on and off, I've tried fast lane in both directions (can connect with 2.4 to router and output 5 just fine but doesn't work the other way). I've reset the extender multiple times, I've reset the router, I've had spectrum work on the router, I've Googled for weeks to fix this. But nothing has even started to fix the issue.
Does anyone have any input on what could be going on? Or anything I could try to fix this issue with?

[plemans]

Problem with 2.4ghz is that it suffers from much more interference. Because of its slower speed, less channels, and the fact that it broadcasts further, more signals impact it much more. 

You can try different 2.4ghz channels on the router to see if that'll help. 

You could try downgrading the firmware on the extender to see if it was a firmware issue. 

Is the shed heated? Exposed to elements? It could also be a moisture/damage/dust issue. 

[SeanPA]

I actually got into the same trouble after a power outage. I don't agree with the issue is due to interference or outdoor too cold. On the same channel where the EX7000 connect to the gateway router, my iPhone or other devices can connect to the gateway on 2.4GHz. The EX7000 2.4GHz radio can connect to the gateway too. Just for some reason, the EX7000 2.4GHz radio doesn't allow anyone to connect. It used to work. Now, those 2.4GHz only IOT devices (plug, camera) cannot connect that is troubling me. 

[ar_wndr3400v3]

I have the same issue. The extender only connects to the router through the 5 Ghz channels. The My wifiext screen shows no connection to the 2.4 GHz. When connecting my phone to the extender it just spins for minutes and not receiving any data. Every other device connects to the 2.4 GHZ frequency to the router (another Netgear device). I tried uploading a previous version of firmware and no change.Netgear would not talk to me unless I pay for support, although the device was like this since I bought it. I can get by with the 5 GHz frequency, but I'd like to get everything I paid for.

[plemans]

@ar_wndr3400v3 please start your own thread and we're happy to help

[rostones]

The issue with 2.4GHz is that it experiences higher interference due to its slower speed, fewer channels, and wider broadcast range, making it more susceptible to signal disruptions.

You can experiment with different 2.4GHz channels on the router to potentially alleviate the problem.

Another option is to consider downgrading the firmware on the extender to investigate whether the issue stemmed from a firmware-related issue.