@Petr89 Thanks for your clarification and I have confirmed as well. It is the security filter rules possessed by the TL-WA850RE which causes this issue; even though you open the port for the...

@ThomasLeeIV It is a beta firmware, please contact our tech support to get it and try to install it. https://www.tp-link.com/support/contact-technical-support/#E-mail-Support Good day.

@it_sergio What is the current network topology? How do you connect these devices together? Meanwhile, please show us a screenshot of the tpPLC utility's page. Good day.

@RedAce What do you mean you can view it on saved network but it won't show up in the wifi list? Can see see it in the wifi list if you forget this network? What about other devices? Can they detect...

@Kaiyuan Thanks for your reply. Please take your time to test, any updates, please let us know. Good day.

@Wilhelm There is no option on the kasa app to verify the amount of data used by the smart plug. While you can check whether the main router supports traffic monitor to get the data value.