A bit late to the party but… I have quite a few of these now; re-flashed from Tasmota -> ESPHome and just set up latest additions that are pre-flashed with ESPHome.
I made the mistake with one of adding it to the wrong WiFi network (one specifically for WiFi connected devices to Home Assistant) - I could not access it via ESPHome / HA and because, as @RebeccaH rightly states, the plug was now connected to a wifi network (the wrong one though!), it stops broadcasting it’s own SSID…
As I could see it in my Unifi controller - I simply blocked it and it immediately began to broadcast it’s default SSID.
This may not be helpful - but it allowed me to then get it successfully connected to the correct wifi network and then ESPHome in HA found it straight away…