ESPHome 2025.10.3 - Error binary size: Unknown error from ESP

[adampetrovic]

Flashing an Athom Plug V3

INFO Package configuration completed successfully
INFO Package configuration completed successfully
INFO Successfully compiled program.
INFO Connecting to 10.0.23.36 port 3232...
INFO Connected to 10.0.23.36
INFO Uploading /config/.esphome/build/switch-dryer/.pioenvs/switch-dryer/firmware.bin (1500608 bytes)
ERROR Error binary size: Unknown error from ESP

I have two V3 switches, flashing them with the stock firmware via Tasmota's UI works fine, but then taking control via the ESPHome WebUI gives the above error when attempting to flash.

Please advise how to resolve this.

[adampetrovic]

Flashing via the device's built in Web UI + OTA feature suffers the same issue (OTA begin failed: 255)