Once you have imported your show, you need to redirect your RSS feed from Bumpers to Acast.
You need your new Acast RSS feed URL. It will be something like https://feed.acast.com/public/shows/mypodcast
This is your Acast feed URL. Copy it to your clipboard.
Redirect your feed
Log in to your Bumpers account.
Go to the Series Redirect page
Select your series, enter your Acast RSS feed URL, and click Save.