@kimot thanks you've definitely given to me the right direction to look into.
Looks like my chip info is different and is the following:
esptool.py v2.6 Serial port COM7 Connecting.... Detecting chip type... ESP8266 Chip is ESP8266EX Features: WiFi MAC: ec:fa:bc:86:da:e2 Uploading stub... Running stub... Stub running... Manufacturer: 5e Device: 4014 Detected flash size: 1MB Hard resetting via RTS pin...
I see that manufacturer 5e is given problems to many people so I've followed the advice I found here https://forum.micropython.org/viewtopic.php?t=3777 to actually solve the issue, specifically flashing with the
-fm dout flag (e.g.
esptool.py --port COM5 write_flash -fs 1MB -fm dout 0x0 file.bin) and now it works!