Do you also have one of new Sonoff DOUT devices?
OTA on these devices normally fails as most of available bin files do not support DOUT flash mode.
Here is the solution of your problem…
For initial flash over serial I use FLASH_DOWNLOAD_TOOLS_V126.96.36.199
This tool has option “DoNotChgBin”, normally not selected… and it shall stay not selected.
If you flash some bin file, this tool changes original bin file, dependent on chosen options QIO… DOUT etc.
If DOUT is selected it will write changed bin file to it’s temp “_temp_by_dltool\downloadPanel1” directory,
there where the original bin file is, with the same name, and new extension .bin_rep
That new bin file is then DOUT mode compatible 🙂
This way probably any bin file can be converted to DOUT compatible bin file.
Here you can download DOUT version of well known ESP Easy Uploader tool ESPEasyUploaderMega_1024.bin.