Thank you for your feedback !
As discussed by email, the black list option is hidden and can be unlocked with "use list" checkbox :)

Here are all the steps:
1. Open youtube auto like options
2. Click 'use list'
3. Click 'black list mode'
4. Go on a video of a channel that you do not want to like
5. Click on youtube auto like options
6. Click on 'Add creator'
7. Repeat steps 4, 5 and 6 as many times you want
8. Videos of this creator should not be liked anymore

Tips: in white list mode, only creators in list will be liked.

You can visualize all creators in list with the "manage" button