First of all don’t fiddle around with the compose file. because that can have unwanted side-effects. The containers must always be started together with the rest of the stack.
You can stop them manually afterwards, as you did, but this is not really necessary, because when they are disabled in the mailcow.conf the number of processes they can use are limited, meaning they are running basically in an idle state. So you won’t gain anything regarding memory consumption by stopping them.
I don’t know why one is shown as stopped in the UI and the other one isn’t, even though both are running and doing nothing. However, I can tell you that it behaves exactly the same on my instance, and that this is only a cosmetic issue.