The Sizmek MDX connector has been removed from the library of connectors in Funnel as of January 1st 2021. Existing Sizmek MDX sources are no longer importing data either.
This is due to Sizmek no longer supporting Sizmek MDX and you are recommended to use the Sizmek Ad Suite connector instead.
If you have any questions, please reach out to support@funnel.io and we'll help out!