Recently our IT-department got a new batch of Lenovo T450 with Intel AC-7265 adapters.
It didn't took very long till people we're complaining about the exclamation mark problem in Microsoft Windows, again (https://communities.intel.com/message/404801#404801).
Model: Lenovo T450 (20BV001KUK), Windows 7 (64-bit), Intel(R) Dual Band Wireless-AC 7265 (driver version: 18.40.4.2, which includes the latest 18.33.3.2 for the 7265 AC)
Scenario:
The notebook is connected either to a Wi-Fi network (WPA2-Enterprise, 802.1X) or a Lenovo docking-station (ethernet).
Due to a meeting or whatsoever, the employee has to leave his working place with the notebook.
After moving around with the notebook the device will not roam to a AP with the same SSID at some unknown point.
I debugged the situation with Netsh, while the notebook is in that fault condition.
NetSH tells me, that the adapter is not connected at the moment (netsh status disconnected).
The list of seen networks (BSSIDs) is filled with known Wi-Fi networks, but the Intel 7265 module won't automatically connect to it.
Wireshark Packet Capture (monitor mode, with another access point) revealed that the notebook transmits probe requests and gets valid probe response of the nearby wireless networks.
My colleagues told me, only a reboot of the notebook will solve the issue, till next time it occurs.
Our APs are several different LANCOM 802.11ac APs (e.g. L-1310acn, L-822, all QCA-9880 based).
Our first thought was, that the LANCOM APs are to blame.
So I've tried to disable the VHT support (HT Mode) as a workaround for my colleagues, that they are still able to work without network issues.
After some days, at least one colleague was complaining again. He ran into this problem, while been connected to a Cisco infrastructre in some university.
I grabbed a new T450 an tried to reproduce this fault condition on my own.
But I had no luck with this, though.
How can I debug this a little more?
Which information do you need?