WPA3 in 21.02 on TP-LINK TD-W8970

OK - just updated to 21.02 - and as WPA3 is available by default - I switched my desktop (arch linux) to WPA3 - standard wpa_suplicant set up.

Anyway although it could connect - had horrible association problems, and the wifi kept going down. Error messages:

Mon Sep 13 15:29:51 2021 daemon.info hostapd: wlan0: STA e0:b9:a5:7e:f6:75 IEEE 802.11: authenticated
Mon Sep 13 15:29:52 2021 daemon.info hostapd: wlan0: STA e0:b9:a5:7e:f6:75 IEEE 802.11: associated (aid 1)
Mon Sep 13 15:29:52 2021 daemon.info hostapd: wlan0: STA e0:b9:a5:7e:f6:75 WPA: pairwise key handshake completed (RSN)
Mon Sep 13 15:29:52 2021 daemon.info dnsmasq-dhcp[17328]: DHCPREQUEST(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:29:52 2021 daemon.info dnsmasq-dhcp[17328]: DHCPACK(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75 summers
Mon Sep 13 15:29:56 2021 daemon.info dnsmasq-dhcp[17328]: DHCPDISCOVER(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:29:56 2021 daemon.info dnsmasq-dhcp[17328]: DHCPOFFER(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:29:56 2021 daemon.info dnsmasq-dhcp[17328]: DHCPREQUEST(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:29:56 2021 daemon.info dnsmasq-dhcp[17328]: DHCPACK(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75 summers
Mon Sep 13 15:33:49 2021 daemon.info hostapd: wlan0: STA e0:b9:a5:7e:f6:75 IEEE 802.11: authenticated
Mon Sep 13 15:33:50 2021 daemon.info hostapd: wlan0: STA e0:b9:a5:7e:f6:75 IEEE 802.11: associated (aid 1)
Mon Sep 13 15:33:50 2021 daemon.info hostapd: wlan0: STA e0:b9:a5:7e:f6:75 WPA: pairwise key handshake completed (RSN)
Mon Sep 13 15:33:50 2021 daemon.info dnsmasq-dhcp[17328]: DHCPREQUEST(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:33:50 2021 daemon.info dnsmasq-dhcp[17328]: DHCPACK(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75 summers
Mon Sep 13 15:33:54 2021 daemon.info dnsmasq-dhcp[17328]: DHCPDISCOVER(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:33:54 2021 daemon.info dnsmasq-dhcp[17328]: DHCPOFFER(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:33:54 2021 daemon.info dnsmasq-dhcp[17328]: DHCPREQUEST(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75
Mon Sep 13 15:33:54 2021 daemon.info dnsmasq-dhcp[17328]: DHCPACK(br-lan) 192.168.2.187 e0:b9:a5:7e:f6:75 summers

This is on an TP-LINK TD-W8970 openwrt router. In the end I've given up and switched back to WPA2 ...

Any ideas?