Poor Wi-Fi signal with a PCIe card.
Poor Wi-Fi signal with a PCIe card.
Confirm the iPhone is using the identical WiFi network and not cellular data. When performing a speed test, make sure cellular data is disabled. Check if the PC is connected to either 2.4GHz or 5GHz wireless signals. Ask about the reported link speed on Windows while connected to WiFi. If the access point uses the same SSID for both radios, consider setting a preference for 5GHz or 802.11ac in the adapter settings. Also, verify if there is only one wireless network available in the office.
The iPhone and PC are likely using the same wireless connection. I've confirmed both 2.4 GHz and 5 GHz signals work on both devices. Windows shows comparable speeds to Ookla's results.
Adapter connection rate is what matters, not the test outcome.