Sudden Wifi problems

[#1]

Hi,

Since yesterday I started having some massive problems getting some of my devices connected to the Hub/Internet via Wifi. This is especially strange as some of them haven't been updated in a while and no configurations were changed proactively from my side.

The devices affected are a MacBook Air running Ventura, an iPhone and an iPad (both iOS 17, both worked fine the first day).

My home setup consists of the Hub, a TP-Link AC1900 range extender, various TP-Link Kasa Smart home devices, 1 iMac (2017), 1 M1 MacBook Air, 2 iPhones 2 iPads, an Apple TV, a Samsung TV, a Thinkpad and 2 Raspberry Pis.

I first started having these problems yesterday around 6pm when my MacBook Air failed to connect to the internet. I haven't used it for a couple of days and no updates or config changes have happened in between. Although it showed that it was connected to Wifi, a grey triangle appeared in the Wifi menu as soon as I tried using Safari stating that there was no internet connection. Curiously, I could not even open the Hub configuration window in Safari although the MacBook claimed it was connected to the Wifi. Everything worked perfectly fine when I connected it to the Hub directly via USB-C. I could also go on the internet via Wifi using my phone as a hotspot.

I tried numerous things to get it working with the Hub again, including rebooting the MacBook and Hub multiple times, updating the MacBook, adding a new network location on the MacBook, changing the DNS settings, erasing the cache, and renewing the DHCP Lease. Noting seemed to help. I reverted all changes. Eventually, I noticed the following: Waking up the notebook from sleep it seems to connect to the Wifi and e.g. Universal Control between the iMac and Macbook works instantly. On the other hand, connecting to the internet or Hub interface starts working but only after a wait time of 1-2 minutes completely unannounced. In all the time that I owned this notebook, this has never been the case before. Everything worked instantly.

Now, although my MacBook is somewhat back to working order again, I have lost the ability to connect to Wifi with my iPhone and iPad (both iOS17).

Both worked flawlessly throughout the day until the evening (9 pm). Every time I click on my Plusnet Hub in the Wifi menu the little spinner icon continues to spin forever without connecting to Wifi or giving up and returning an error message. This goes for both the Hub and the range extender. I dug out an old TP-Link TL-MR6400 300 Mbps 4G Mobile Wi-Fi Router and I can connect to that one with both devices instantly and without any problem at all.

On the other hand, the Raspberry Pis (one via ethernet, the other via Wifi) work perfectly fine. My Kasa Wifi-based smart home stuff is also not giving me any problems. All of those work fine even after multiple Hub reboots.

I am really confused as to what is going on. Does anyone have any ideas?

[#2]

Update:

Now my iPad suddenly managed to connect to the Hub by itself (I randomly noticed that it is connected). The internet does not work on it but I am able to control Homekit devices and connect to the Hub UI...

[#3]

Update 2:

Through a lot of trial and error, I managed to get my devices running again.

For all four devices affected, I had to configure the IPV4 address manually and set a DNS server manually (in each device's settings). Now all of them connect to Wifi instantly again and the internet is working instantly as well.

 Does anyone know what could have triggered this and why this became necessary?

[#4]

Update 3:

There seems to be a problem with the WiFi-DHCP of the Plusnet Hub. But I cannot establish a pattern....

When I connect my MacBook via ethernet and DHCP, everything works instantly.

When I connect my MacBook via WiFi and DHCP, it takes about 2min until I can access the internet or the router settings.

When I connect my MacBook via WiFi and configure the settings manually, everything works instantly.

When I connect my iPhone 13 via WiFi and DHCP, it never establishes a proper connection but also does not seem to stop trying (the spinner icon just spins perpetually, usually iOS returns an error message if there is a problem or a WiFi router has no connection to the internet).

When I connect my iPhone 13 via WiFi and configure the settings manually, everything works instantly.

When I connect my Apple Watch via WiFi and DHCP, it never establishes a proper connection but also does not seem to stop trying (the spinner icon just spins perpetually). There is also no option to configure the settings manually... The router however shows it in the log:

09:15:27, 23 Sep.	ath00: STA f5:14:3d:69:8c:8d IEEE 802.11: Client associated
09:15:27, 23 Sep.	ath00: STA f5:14:3d:69:8c:8d IEEE 802.11: Client disassociated

Confusingly, when I connect my iPhone 13 Pro Max via WiFi and DHCP, everything works instantly.

Other devices, e.g. my SwitchBot Hub Mini, which does not have the option to configure the settings manually, also work perfectly fine.

[#5]

Update 4:

To resolve the issue with my Apple Watch I ended up disabling the Apple WiFi privacy settings on the watch and running a second DHCP server on my Raspi (isc-dhcp-server) that assigns it the following settings

host deviceName {
    hardware ethernet AA:BB:CC:DD:EE:FF;                                    # Replace with the device's MAC address
    fixed-address 192.168.1.XX;                                                        # Set the static IP
    option subnet-mask 255.255.255.0;                                             # Set the subnet mask
    option routers 192.168.1.254;                                                      # Set the IP of the router
    option domain-name-servers 208.67.222.222, 208.67.220.220; # Set the DNS for the device
}

Now I have WiFi and internet on the Watch as well.