Niel wrote:
If they were previously paying for more than one of the other individual services and then signed up for Apple One, there won't be a trial period; this is done so they can start saving money.
If they had any trial time remaining for them, it'd show in the screenshot.
(223126)
There would be a month trial period for any services they weren’t paying for.
During that trial period any services you were already subscribed to, would remain in whatever state they were even if that is their own trial period.
Once Apple One renews into the paid subscription all covered services are moved under the Apple One umbrella.
Since the OP cancelled Apple Music they are not eligible to access it while the Apple One trial is still ongoing for the other services as stated in the support document.
From: Bundle Apple subscriptions with Apple One - Apple Support
Apple One includes a free 1-month trial for services that you don’t already have. After your free trial, services that you previously subscribed to are automatically included in Apple One. If you recently canceled a service, you might not be eligible for the free trial.