The majority of my wireless clients that a human will actively notice an issue with are apple devices (macs and iphones). The wireless client with the worst behavior (to the point that the user uses her iphone as a hotspot for unlimited data instead of the wifi) is an HP laptop running windows 10. She reported that her laptop constantly disconnects, which is why she switched to the hotspot.
I probably should have started a new thread rather than hijacking this one. This is definitely only a problem for wireless clients using the AP One AC Mini access points. Wired clients have no discernible issues.
I have one 2 story structure on the property, and 2 single story structures. In the 2 story structure, I have one AP One AC Mini on each floor, and one each in the 2 single story structures. There is gigabit fiber trunking between all the switches, and PoE+ switches powering the AP One AC Minis.
In order to do extra troubleshooting yesterday, I put the older apple time capsule devices' wifi (the ones these peplink devices replaced) back online in the 2 story structure and one of the 1 story structures, and turned off the radios in the AP One AC Minis in those structures. I configured the AP One AC Mini in the remaining structure to disable the 5GHz band and run the 2.4GHz radio at medium power. This is the structure with the windows 10 client, as well as one tp-link wifi->ethernet bridge device (tl-wr702n in client mode). The tp-link has been solid all along. I haven't had a report from the windows laptop user yet.
Also, the router is a Max Transit Duo with 2 unlimited cellular uplinks. When I've experienced the issue on my laptop, I can ping the router IP and even ping 22.214.171.124 but running "curl google.com" hangs. Initially I thought this was a Mac issue, but I've recently had the windows client added to the network, also being affected, and I've also learned that the wired macs don't have this issue, leading me to investigate the AP One AC Mini units.