Spotify for Podcasters unfortunately does not allow podcasts hosted with Acast and several other hosting companies to upload a video version to Spotify. The reason for this is that, currently, video podcasts are incompatible with DAI-supported audio podcasts.
Your Acast user agreement stipulates that uploading a separate video version of your podcast to Spotify, which would create a separate RSS feed, violates the exclusive rights you've granted to Acast to distribute your podcast. The separate/duplicated RSS feed would not be monetizable via Acast and would not display any data in your Insights dashboard.
As such, you are not allowed to upload a video version of your podcast to Spotify. Spotify is aware of this issue and we hope that it is resolved soon. In the meantime, we appreciate your patience.