Unifi dhcp timeout nightmare

Hello all. Since @LTS_Tom likes to use unifi (as do we) I thought I would bring up a nagging issue with dhcp timeouts using firmware 4.x and above. We upgraded one our site’s to the latest firmware on 4 AP AC pros along with deploying a cloud key gen 2. Most of the devices on this network are Apple. All of a sudden people started complaining about dhcp timeout errors and not getting IP’s. So after some research this appears to be a massive ongoing issue that ubiquity can not seem to resolve. We are at the latest firmware for all devices and some people have had luck downgrading to 3.9.
But I am just trying to get a consensus from other unifi users to see if this is haunting them.

Oddly, in the latest firmware we turned on the fast roaming and all the Apple WiFi issues went away for one of our client who has about 20 iPad POS systems.

Interesting. I did read somewhere where people were noticing the apple devices would fail when they roamed from AP to AP. But I also read where this cause more issues. Also there was a reference to lowering the power spit out by these aps. Anyway we will give it a go.

Thanks Tom

Hello All…Just in case others are having this issue I did the following and it fixed the issue for me with the Apple devices. It is night and day.

I created a new WLAN and in the new WLAN create an SSID on it and make sure that the “AUTO-OPTIMIZE NETWORK” under Settings > Site is OFF and disable the feature “Block LAN to WLAN Multicast and Broadcast Data” in the SSID settings. Also, under SSID settings there is configuration called " 802.11 RATE AND BEACON CONTROLS" make sure you set the DTIM to 3 for 2G and 5G.

I believe the key was changing the DTIM to 3. All the other settings were already there.

Good day i am also still having the same issue. I am using UNifi Controller Version 5.14.23 (Build: atag_5.14.23_13880). I am using 4 UNIFI-AC-MESH all on the lastest firmware version 4.3.24.11355. Randomly WiFI devices fail to get an ip address. I am using a Mikoritk RB951(Running the latest firmware 6.47.8 its running the hotspot as well as the DHCP. When they are working the work really well but this DHCP issue is really a problem. I also have devices connected on the mikrotik lan and they never have issues.

Finally there seems to be a fix from unifi
https://community.ui.com/releases/UAP-Firmware-4-3-26-11358/e05cd041-ea54-460c-85f4-7f3fd97261e8

Seems issue has not been solved in this version. i still had the same issue