Yes, I checked it several times, put the passphrase in quotes and even copy pasted the walletpassphrase command to the console of the debug window of the PC wallet. The PC unlocks, the Pi doesn’t.
Can someone maybe just give it a try and see if it works?
EDIT: lol nevermind, I forgot that I changed it on the Pi some time ago and it was forever unlocked for staking. Everything is fine. Thanks for the binary @CoinGame!