hub 2: Not allowing devices to connect (not allocating IP addresses?? ).

[#1]

Had this problem for a while with hub 1, but was infrequent (well several times a day). Worsened - contacted customer support who changed something and assured it was fixed (guess what not fixed). They send me a hub 2 which would fix it.... Phoned again today and they changed something to fix it....... 

Trying this as fed up waiting on phone. 

Rough set up (not really understand tech stuff but here goes).

Fibre to box, copper to house. Moderate distance away. 

New hub 2. Connects to internet first time every log suggests that no drop outs. Lights blue on hub. I have just done a factory reset and turned off for 2  minutes and back on again. Not helped.

The hub connects to 1 Laptop (about 2 years old) and a printer via 2.5gz (it has 5gz but chooses not to connect that way). This PC & printer are affected by the problem, but not quite as bad as rest of devices - maybe 5 or 5 times an hour.

The hub connects to 1 PC (6 months old) on 5gz and it always connects and stays connect. Can disconnect and reconnect with no problem. 

I then have 3 wired WAP around the property. All 3 WAP go via a switch down 1 cable into port 3 on router. Maybe 50 different devices. IP cameras, smart switches, TV, ECHO, phones, chromebooks, laptops etc. At one point these would connect for a couple of minutes and then disconnect, reconnect etc... Then that slowed to connecting for 1 min and disconnecting for 10 etc. Now only occasionally will one connect to the hub. 

since reset half hour ago the hub is showing 1 smart switch successfully connected and 7 other devices tried but failed.

I think it is not allocating secure IP address to the devices.

HELP

[#2]

What is the make/model of the wireless access points and are they cabled directly via the switch? i.e. not via Powerline adapters.

Is the Wi-Fi on the Hub Two enabled or disabled?

Are the wireless access points using the same SSID/Wi-Fi name/password?

[#3]

Moderators Note

This topic has been moved from Broadband to My Router

[#4]

Everything worked until recently,

WiFi enabled on hub 2. Name xxxx1 for both 5g & 2g.

Cat 5 cable then goes some distance away - about 50m. Into the switch which has 4 ubiquiti access points (wired back to switch with cat 5 cable). And 4 TP link CPE210 - all 2g and named xxxx2g the same as .......:The ubiquiti: 2 are "pro" and just 2g, other 2 are "lite" 2g & 50g All wifi named xxxx2g or xxxx5g.

I just used one of the tplink access points with my phone for 10 minutes. Before I was thrown off and now my phone will not connect. But at least the access point is now connected to the router.