Platform: macOS 26.3.1, M5 Pro MacBook Pro Framework: CoreWLAN Affected applications: NetViews, Air Tool 2, and our own tooling — appears to be specific to the new Wi-Fi 7 hardware Hardware Card Type: chip id: 0x11 api 1.2 firmware [Rev 72.11.260 N1B1 devFused=0] phy [17.1.17.0], core80211 [324.10.260 N1_silicon_b] Firmware: Jan 27 2026 21:18:32 version XBS_BUILD_TAG GIT_DESCRIBE FWID chip id: 0x11 api 1.2 firmware [Rev 72.11.260 N1B1 devFused=0] phy [17.1.17.0], core80211 [324.10.260 N1_silicon_b] Driver: IO80211_driverkit-1540.16 "IO80211_driverkit-1540.16" Jan 27 2026 Background Both issues described below were working correctly on macOS 26 with previous-generation hardware. The regression is specific to the Wi-Fi 7 card shipping in the M5 Pro MacBook Pro. This is not an OS regression — it is a hardware/driver/firmware compatibility issue with the new card under macOS 26. Issue 1: disassociate() + tcpdump/Wireshark -I no longer enters monitor mode Previously, the standard approach of calling disassociate() and then launching tcpdump -i en0 -I or Wireshark -i en0 -I -k would successfully put the interface into monitor mode. On the M5 Pro Wi-Fi 7 card, this no longer works. The capture tool launches but the interface either stays in station mode or enters mode 0 - where there is no connection, but still not able to be a monitor radio. This is the primary regression affecting third-party wireless tools. Issue 2: setWLANChannel reports success but the radio only retunes once As a workaround for Issue 1, we use the built-in Wireless Diagnostics → Sniffer tool to establish monitor mode (which works fairly reliably on this hardware). Once the interface is in monitor mode via that path, we attempt to change the channel using setWLANChannel: let iface = CWWiFiClient.shared().interface(withName: "en0")! let target = iface.supportedWLANChannels()! .first { $0.channelNumber == 6 && $0.channelWidth == .width20MHz }! try iface.setWLANChannel(target) The first call succeeds (eg: channel 48 -> 6) the radio actually tunes to the requested channel and Wireshark captures frames there. Any subsequent call (eg: channel 48 -> 6 -> 1) shows the same apparent success - no error thrown, wlanChannel() updates to reflect the new channel - but the radio does not retune. Wireshark continues capturing on the first changed channel. We have tested with disassociate() and interface power cycling between attempts — neither resets the ability to retune the radio. What we have ruled out Timing: delays between calls make no difference Competing processes holding the interface wlanChannel() returning a stale cache value — it updates correctly, but diverges from actual hardware state after the first channel change Key data point: Wireless Diagnostics Sniffer works The built-in Wireless Diagnostics → Sniffer tool successfully puts the interface into monitor mode on this hardware. This confirms the card and driver are capable - the issue is that the capability is no longer reachable via CoreWLAN or via tcpdump/Wireshark's -I flag. Wireless Diagnostics Sniffer does not support live channel changes, so it cannot serve as a full workaround. The questions Is there a supported path for third-party apps to enter monitor mode on the new Wi-Fi 7 hardware on macOS 26? What is the correct mechanism for changing channels while in monitor mode - is setWLANChannel expected to retune the radio on subsequent calls, or is there a different API intended for this? The fact that Wireless Diagnostics accomplishes both (albeit, not live) confirms the hardware and driver are fully capable - we are looking for the sanctioned equivalent for third-party tools.