@soggycashew
Firmware v1.0.1 has some bugs and one of them is that it only saves config to SD card and not to the EEPROM.
Try this:
- Check your FW version from info screen, it likely is 1.0.1, at least mine was (and still is) when I got my Ender 3 V2
- Remove SD card if you have it plugged in
- Change something like E steps as you mentioned to 144
- Go to Control screen and select 'Storage configuration' (likely a typo as it probably should say 'Store configuration')
- Turn off printer
- Turn on printer
- Go to verify E steps and the setting is back to original value 93 just like you already saw with your printer
- Now insert SD card to the reader
- Repeat steps from 3 to 7 and this time E steps should be 144
I suggest you check YouTube videos how to upgrade to newer FW version, there's plenty already available.
For example CHEP has this video which also mentions the very same problem you saw:
https://www.youtube.com/watch?v=dLZm2itXJkg
If you do not want to upgrade FW then either just keep the SD card plugged in when printer boots up or after inserting it go to Control menu and select 'Read configuration' to load settings from the SD card.
As far as I know the EEPROM.DAT file in the root of the SD card is the one with saved settings.
Like said I haven't yet upgraded my printer so I just ended up adding following line to my printer Start G-code section in Cura slicer: "M92 E415; Set new e-step value for BMG extruder".
So far everything has been working just fine and my prints look great even with the 1.0.1 FW version.