booooop [any]

Alright so no permission issue, what if you run the changekey command in a separate bash subprocess? sudo bash -c '($your-changekey-command-here)'

What is the output if you run sudo cryptsetup --verbose open --test-passphrase /dev/nvme0n1p3?

If testing this properly is your problem you should invest time in integration testing, running them on an in-memory database is an option as well. I think retrieving all the data and “caching” it like you call it has some negative consequences, for example what if the validation for some action fails and you didn’t need to load whatever you preloaded? Waste of a call to the db