Maybe only etcher has problems velidating checksum?
Seriously? If Etcher is reporting a problem it's not an Etcher problem but Etcher reporting writing failed (a hardware problem!).
Only solution: throw the card away. Or suffer from strange problems later you'll attribute to 'OMV is broken' instead 'my card or writer is corrupting data'.
And wrt resizing AGAIN the link: Expand root system to use all of SD card (and if you follow there the last link -- that's the blue stuff -- you see how to proceed if you want to use a SD card too small)
