I'm running latest app version and smart plug firmware at the time of writing.

Problem 1: If I press the side button the state takes too long to be shown on the app. It takes anywhere between 3 and 12 seconds. Everything is connected through local Wi-Fi. Interestingly, the power state updates immediately on Alexa.

Problem 2: If I physically disconnect the smart plug, the app does not show the device as "offline" or "unreachable", it simply shows the last known power state. If there is a power cut I would look at the app and think the device was on, when in fact it is not. Philips Hue smart plugs are grayed out when they become unreachable.

Problem 3: If I toggle the power state on the app, it changes immediately on the app, even if the plug not actually plugged in. Then, after a few seconds, when the app notices the device is not reporting a change of state, it reverts back to the previous state, whether it is correct or incorrect. It would be better to have a "working" state, where the on/off button in the app flashes to indicate that the app is trying to execute the user's command. If the device is unreachable, it should then be grayed out to indicate that (see previous point).

I have uploaded a video to YouTube to show all of this, you can watch it here.

Unless TP-LINK confirms these issues will be resolved soon, I will be returning these plugs within the next few days.