I'd start by connecting a PC with an ethernet cable to the netgear switch where the AP11 is connected.
Use the inventory page to check the ethernet port of the AP11, hopefully this is 1000MB/full.
Does it obtain an IPv4 address in the same network as the AP11 ? (use the AP list in the inventory screen to find the AP11 IPv4 address)
Run the throughput testing - here, we expect pure ethernet, so the results should be pretty close to the 200MB (providing the test server can accommodate) and verifies that portion of the path.
ping the AP11 - what does the RTT and loss look like ? Expect loss <1% and RTT < 5ms. if not, check netgear port, cable, and perhaps the AP11.
Connect the other APs in the same fashion. These should also have IPv4 addresses in the same network.
Inventory -> add devices should display the new device and allow them to be added to the network.
Clients:
disabling the 3g/4g in the phone, or test with a device that only has the 802.11 interface.
See if this device remains stable with good connectivity, low loss, and expected throughput, then move to testing the phone (without the 3g/4g enabled) . The client screen should show "good quality" signal.
It's critical to know which frequency band the client is connected, 2.4ghz 20Mhz wide , with a 1x1 client, 72.2Mbps is the maximum you'll see - speedtests are usually TCP, so 30Mbps sounds about right. With a 2x2 client 144Mbs is theoretically possible. It's interesting to watch the AP utilization during such tests.
Important is that all clients obtain good and consistent service at the same time.