WLAN card no longer properly initialized under 2.4.0
I have installed pfSense on an APU2C4 (bios 4.0.7) with a 32 GiB mSATA and a Compex WLE200NX (Atheros AR9280).
I did a fresh installation on this hardware with pfSense 2.4.0 because I want a GPT/ZFS installation. I could restore my 2.3.4p1 configuration from the webGUI and the machine is working fine except one smaller WLAN related issue.
The WLE200NX card is cloned and configured for 11an mode. This configuration worked very stable unter 2.3.x at 5 GHz and an automatically selected channel width of 40 MHz. Now under pfSense 2.4.0 I can observe to issues:
1.) After every reboot the card is initialized in 11ng mode instead of 11na.
2.) I can force the card in 11an mode by just saving the settings on the interface configuration page of the webGUI without doing any configuration changes. However, the card never uses 40 MHz channel width.
Is this a known issue? If so: Should I create a ticket in the bug database?
I have created following related issue in the bug database: https://redmine.pfsense.org/issues/7986