Mobile clients sometimes hanging for an eternity

[soldadozka]

Holidays are here, lots of family members gathered at my parents house and I got a bunch of complaints from them about the wifi. The setup is:

• one RT-AC87U on 384.13_2 (main router),
• one RT-AC66U_B1 on 384.14 connected through cable (AP mode),
• one Raspberry Pi for Pi-hole (connected through cable to the main router), and
• one TP-Link WR840N connected wireless with the lowest broadcasting settings (this is only needed for the solar panel systems wifi adapter, because the inverter is in the garage and that area of the house doesn't really need wireless connection)

Since I'm not living here, I had no idea about these problems when I installed this setup (about 3-4 months ago), and now that I'm spending a longer time here I have the time to investigate/fix the problem. I found out that it doesn't really matter if there are 40-50 or only 4-5 clients connected to the routers, only the mobile phones have this problem, and it doesn't happen at regular intervals, sometimes (after 10-15 minutes of browsing? this is just a guess) it just decides that it won't load anything you want to see on your phone. If I turn off wifi on the phone and turn it back, then it works again.
PCs and Macs are fine, as well as consoles and Smart TVs, I could only reproduce this on Android and iOS, both on the older devices like Samsung Galaxy S6 or iPhone 7 and on the newest ones like Samsung Galaxy S10e or iPhone 11.

First, I disabled Pi-hole for 2 hours to see if the problems still occuring (but it didn't help), then I tried to play around with some settings on the Professional tab I found on the forum but none of them fixed my problem - some pictures of the settings: https://imgur.com/a/lZXaH5C

As I'm starting running out of ideas, I came to you guys to ask if you have any ideas about the cause and the potential fix of this problem. Any help appreciated!

Thank you in advance! Happy holidays!

 

[ColinTaylor]

My guess is that it's only happening to the mobile phones because they are the only devices that move around. So they're probably connecting to one AP and then "sticking" to it even when they move away and the signal becomes weak.

 

[soldadozka]

The roaming assistant setting should help on that, but the hanging happens even when I don't move (e.g. sitting on a couch or laying in the bed).
Maybe I should do a recheck for that setting with a phone, because when I tried to find the best one, it was with a Macbook.

 

[DigitizedMe]

Messing around with this today, and I can confirm device hand off isn't working using same SSID and different channels, on 5 GHz only. Roaming assistant doesn't appear to do anything even if I set the RSSI threshold super low between my two APs. However, it will swap to a 2.4 GHz channel if dual band is enabled.

 

[soldadozka]

Good catch, thank you! I was experimenting with this too, but I didn't see any differences, so back to the same channels.