@Joseph-TP As you can see from the comment above that another user is also facing similar issue. It might be an issue in the 1.2.3 firmware. Can you please let me know how to downgrade to older...

@Joseph-TP Yes my router is in access point mode and is connect via ethernet cable to my main(non tp-link) modem/router which was provided by my ISP. Before the update it was working fine in access...

Everything was working as intended since past 1 year until I updated my Archer BE400 yesterday to firmware 1.2.3 Build 20260107 rel.48335(5553) after a notification popped up in the router web...