Error with device about to be added

Previously, I was able to pair some Matter devices to the Deco app (smart plugs) including TP-Link Kasa powerstrip KP303. Recently, I saw an announcement of new WiFi heat map feature rolling out to beta users (https://community.tp-link.com/en/home/forum/topic/854924) so naturally I signed up via iOS' Testflight and install it. To no surprise, I don't see such feature appearing in Deco Lab section of the app, so deleted the Deco Beta app reinstalled the stable-release app from the App Store.

However, none of my previously paired Matter devices nor the TP-Link Kasa devices showed up in the Deco app. I've tried pairing them all one by one, it keeps throwing random errors and at one point, it even knows that it was added before but nothing shows up in the app. I tried resetting the Matter devices itself completely and re-pairing with Deco, nothing worked. The devices can be paired just fine with other Matter controllers like Apple HomeKit, Google Home and Alexa. But none of it pairs with Deco app anymore.

And when I thought it can be paired, it always errors out when assigning a location to that device. No matter which selection I made, the device was never added. I've checked each devices in Matter section of the iOS Settings app, it says its connected to TP-Link but nothing shows up on Deco app.