The behavior you describe suggests that your WiFi connection is receiving interference from the Bluetooth* adapter. Please check the following items that related to this:
- Bluetooth* operates in the 2.4 GHz band, so it may cause interference, specially with 2.4 GHz WiFi.
- The Intel® Dual Band Wireless-AC 8260 has 2 antennas, one of them is shared with the Bluetooth* component.
The main recommendation we can provide is to confirm you are using updated drivers for WiFi and Bluetooth*:
If possible, connect to a 5 GHz wireless network and check if you get the same issue.