WRT32X - specific wifi client deauthenticated after 10 seconds

Running 23.03.0
I've seen it in the past but disabling "Disassociate On Low Acknowledgement" has fixed this previously.

I've changed some settings that previous threads have suggested.

config wifi-iface 'default_radio1'
        option device 'radio1'
        option network 'lan'
        option mode 'ap'
        option macaddr 'xxxxxxx'
        option ssid 'yyyyyy'
        option encryption 'psk2'
        option key 'zzzzzz'
        option skip_inactivity_poll '1'
        option max_inactivity '43200'
        option disassoc_low_ack '0'
Here's what happens with it:
Sep 23 17:19:37 OpenWrt hostapd: wlan1: STA e8:db:84:8f:12:7c IEEE 802.11: associated (aid 15)
Sep 23 17:19:37 OpenWrt hostapd: wlan1: STA e8:db:84:8f:12:7c IEEE 802.11: authenticated
Sep 23 17:19:37 OpenWrt hostapd: wlan1: AP-STA-CONNECTED e8:db:84:8f:12:7c
Sep 23 17:19:37 OpenWrt hostapd: wlan1: STA e8:db:84:8f:12:7c WPA: pairwise key handshake completed (RSN)
Sep 23 17:19:37 OpenWrt hostapd: wlan1: EAPOL-4WAY-HS-COMPLETED e8:db:84:8f:12:7c
Sep 23 17:19:48 OpenWrt hostapd: wlan1: AP-STA-DISCONNECTED e8:db:84:8f:12:7c
Sep 23 17:19:48 OpenWrt hostapd: wlan1: STA e8:db:84:8f:12:7c IEEE 802.11: disassociated
Sep 23 17:19:48 OpenWrt kernel: [ 5329.566764] ieee80211 phy1: staid 15 deleted
Sep 23 17:19:49 OpenWrt hostapd: wlan1: STA e8:db:84:8f:12:7c IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)

This device will connect to an access point on my phone no problem.
I tried going back to v19 firmware earlier today, but that didn't seem to solve the issue.