Just chiming in with a 'me too' on 9313 firmware, I had just updated 2 days ago and sure enough my laptop been saying 'dns' issues even though there was no issue with DNS as far as I could tell, checked router logs and saw a lot of this:
Dec 12 05:23:56 hostapd: eth7: STA [REDACTED MAC] WPA: group key handshake failed (RSN) after 4 tries
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Deauthenticated because sending station is leaving (or has left) IBSS or ESS (3)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 hostapd: eth7: STA [REDACTED MAC] IEEE 802.11: disassociated
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:58 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Dec 12 05:23:59 wlceventd: wlceventd_proc_event(464): eth7: Deauth_ind [REDACTED MAC], status: 0, reason: Class 3 frame received from nonassociated station (7)
Pasting this in here for google crawlers so people see this is an issue with 9313 firmware on the ax86u.
To add this seemed to effect 2.4GHz too for me at least, though it could have just been network change and me being too impatient. In any event rolling back to 9298 fixed everything, which you can manually do by going to
https://www.asus.com/us/Networking/RT-AX86U/HelpDesk_BIOS/ and then downloading and unzipping the zip and then manually uploading the firmware. Hope this helps someone, from release notes it does not seem that 9313 firmware had any security updates so I see no harm in rolling it back to the previous version until this gets fixed.