I've tested this today on both 20.04 (with linux-firmware-raspi2 1.20200212-0ubuntu1~ppa1) and 19.10.1 (with linux-firmware-raspi2 1.20200212-0ubuntu1~19.10.1~ppa1) and neither of them were able to connect to the 802.11ac access point.
I see the same journal entries mentioned previously: Mar 10 20:57:10 ubuntu wpa_supplicant[1090]: wlan0: Failed to initiate sched scan Mar 10 20:57:18 ubuntu wpa_supplicant[1090]: wlan0: Failed to initiate sched scan Additionally, I notice that the output of 'iw dev' shows different channels and widths than on Raspbian: Interface wlan0 ifindex 3 wdev 0x1 addr dc:a6:32:37:37:08 type managed channel 128 (5640 MHz), width: 20 MHz, center1: 5640 MHz txpower 31.00 dBm -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-firmware in Ubuntu. https://bugs.launchpad.net/bugs/1862760 Title: Unreliable 802.11ac connection on our raspi images Status in linux-firmware package in Ubuntu: New Status in linux-firmware-raspi2 package in Ubuntu: New Status in linux-raspi2-5.3 package in Ubuntu: New Status in linux-firmware source package in Bionic: New Status in linux-firmware-raspi2 source package in Bionic: New Status in linux-raspi2-5.3 source package in Bionic: New Status in linux-firmware source package in Eoan: New Status in linux-firmware-raspi2 source package in Eoan: New Status in linux-raspi2-5.3 source package in Eoan: New Status in linux-firmware source package in Focal: New Status in linux-firmware-raspi2 source package in Focal: New Status in linux-raspi2-5.3 source package in Focal: New Bug description: We were not able to completely pin-point the issue yet, so this is more of a blanket bug for the current issues we are seeing. We don't know where exactly the issue can be located. While preparing and testing 18.04.4, certification reported issues with our uc18 images on the pi4 with wifi ac tests. One of our engineers (Brian) confirmed it locally with a wifi access point restricted only to 802.11ac. After some additional testing, he noticed that he had the same unreliable symptoms for both the classic and core images, as well as the 19.10.1 classic images. The symptoms seem to vary, from inability to detect 802.11ac APs, inability to connect and/or receive an IP address and no traffic getting through. We will provide all the information that we have. Raspbian works better in this regard. We have pulled in the wifi firmware bits from Raspbian and using those, and that seems to resolve all flakiness. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1862760/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp