I'm currently developing a board that uses the RPi CM3+ and I've been noticing an unusal issue on it.
Sometimes when it is powered up or rebooted it seems like the data has corrupted on the EMMC, however other times it boots up perfectly fine. Along with this I have re-flashed the EMMC and the issues come back so I don't believe it's a once off bad write.
I'm fairly certain it is along the lines of corruption as either it'll refuse to SSH in with the error "ssh_exchange_identification: read: Connection reset by peer" possibly indicating corrupt SSH Keys. And if I can get logged in I get errors such as "-bash: /bin/ls: Input/output error"
Now my main thing is what could be causing this, I have experienced the issues with an 8GB CM3+ and a 16GB CM3+.
The only thing I can think potentially is that the CM3+ datasheet says the supply sequencing should be in order from highest vltage to lowest voltage however I did not implement this staggering into the design (I misread this section) and could potentially explain why it is intermittent.