systemd-networkd MAC address randomization stops working when iwd restarts

Hi,

there's a bug in iwd which may prevent udev from anonymizing the MAC
address of a wlan interface.

Setup: systemd 258.3, iwd 3.8 or 3.11, a wlan iface, which has
"MACAddressPolicy=random", "Anonymize=yes", "ActivationPolicy=manual",
"NamePolicy=kernel path" in systemd and
"EnableNetworkConfiguration=false" and no address randomization in
iwd.

After system boot:

# systemctl start iwd
# networkctl status wlp9s0
(...)
          Hardware Address: a2:ed:29:33:92:3b
Permanent Hardware Address: <physical MAC address, different from address above>
(...)
                   Address: 192.168.0.31 (DHCPv4 via 192.168.0.1)
                   Gateway: 192.168.0.1
                       DNS: 192.168.0.1
(...)
          DHCPv4 Client ID: a2:ed:29:33:92:3b

Everything is working, a random MAC address has been generated. If iwd
is restarted then (daemon crash, systemctl, ...), I expect udev to
continue using the random MAC address or generate a new one. However:

# systemctl stop iwd
# systemctl start iwd
# networkctl status wlp9s0
(...)
        Hardware Address: <physical MAC address>
(...)
                 Address: 192.168.0.244 (DHCPv4 via 192.168.0.1)
                 Gateway: 192.168.0.1
                     DNS: 192.168.0.1
(...)
        DHCPv4 Client ID: <physical MAC address>

IP connection has been re-established, but the MAC address used is no
longer random. "Permanent Hardware Address" is missing from networkctl
list. Following the start of iwd, this is appended to the journal:

Feb 22 22:52:50 krb iwd[3522]: No Diffie-Hellman support found, WPS
will not be available
Feb 22 22:52:50 krb iwd[3522]: The following options are missing in the kernel:
Feb 22 22:52:50 krb iwd[3522]:         CONFIG_KEY_DH_OPERATIONS
Feb 22 22:52:50 krb iwd[3522]: Wireless daemon version 3.11
Feb 22 22:52:50 krb iwd[3522]: Loaded configuration from /etc/iwd/main.conf
Feb 22 22:52:50 krb systemd[1]: Started Wireless service.
Feb 22 22:52:50 krb iwd[3522]: station: Network configuration is disabled.
Feb 22 22:52:50 krb iwd[3522]: Wiphy: 0, Name: phy0
(...)
Feb 22 22:52:50 krb iwd[3522]: event: state, old: disconnected, new:
autoconnect_quick
Feb 22 22:52:50 krb systemd-networkd[2520]: wlan0: Link UP
Feb 22 22:52:50 krb (udev-worker)[3535]: wlan0: Could not set Alias=,
MACAddress=/MACAddressPolicy=, TransmitQueues=, ReceiveQueues=,
TransmitQueueLength=, MTUBytes=, GenericSegmentOffloadMaxBytes= or
GenericSegmentOffloadMaxSegments=, ignoring: Device or resource busy
Feb 22 22:52:50 krb systemd-networkd[2520]: wlan0: Interface name
change detected, renamed to wlp9s0.
Feb 22 22:52:50 krb kernel: mt7921e 0000:09:00.0 wlp9s0: renamed from
wlan0 (while UP)
Feb 22 22:52:50 krb iwd[3522]: udev interface=wlp9s0 ifindex=5
Feb 22 22:52:50 krb (udev-worker)[3537]: wlp9s0: Could not set Alias=,
MACAddress=/MACAddressPolicy=, TransmitQueues=, ReceiveQueues=,
TransmitQueueLength=, MTUBytes=, GenericSegmentOffloadMaxBytes= or
GenericSegmentOffloadMaxSegments=, ignoring: Device or resource busy
Feb 22 22:52:50 krb systemd-networkd[2520]: wlp9s0: Configuring with
/etc/systemd/network/21-wlp9s0-dhcp.network.
Feb 22 22:52:51 krb iwd[3522]: invalid HE capabilities for <MAC>
Feb 22 22:52:51 krb iwd[3522]: event: connect-info, ssid: <SSID>, bss:
<MAC>, signal: -63, load: 15/255
Feb 22 22:52:51 krb iwd[3522]: event: state, old: autoconnect_quick,
new: connecting (auto)
Feb 22 22:52:51 krb kernel: wlp9s0: authenticate with <MAC> (local
address=<physical MAC address>)
Feb 22 22:52:51 krb kernel: wlp9s0: send auth to <MAC> (try 1/3)
Feb 22 22:52:51 krb kernel: wlp9s0: send auth to <MAC> (try 2/3)
Feb 22 22:52:51 krb kernel: wlp9s0: authenticated
Feb 22 22:52:51 krb kernel: wlp9s0: associate with <MAC> (try 1/3)
Feb 22 22:52:51 krb kernel: wlp9s0: RX AssocResp from <MAC>
(capab=0x1411 status=0 aid=21)
Feb 22 22:52:51 krb kernel: wlp9s0: associated
Feb 22 22:52:51 krb systemd-networkd[2520]: wlp9s0: Connected WiFi
access point: <SSID> (<MAC>)
Feb 22 22:52:51 krb iwd[3522]: event: state, old: connecting (auto),
new: connected
Feb 22 22:52:51 krb systemd-networkd[2520]: wlp9s0: Gained carrier
Feb 22 22:52:51 krb systemd-networkd[2520]: wlp9s0: DHCPv4 address
192.168.0.244/24, gateway 192.168.0.1 acquired from 192.168.0.1

systemd has rejected the issue as not theirs and a developer has
provided some background:
https://github.com/systemd/systemd/issues/40787 My full .network and
.link files are in there, too. main.conf:

[General]
EnableNetworkConfiguration=false
DisableANQP=false
DisableOCV=false
Country=CZ
DisablePMKSA=false
[Network]
EnableIPv6=false
NameResolvingService=systemd
[Scan]
DisablePeriodicScan=true

Thanks,
Roman