Was watching Haven TV series on Acorn/Roku until July 31. On Aug. 1 the episodes changed from free to $1.99 per episode on Amazon Prime, but no longer available on Acorn. Why is this series no longer provided with my Acorn monthly subscription?
The streaming content offered for free on different channels is rotated and available depending on licensing. (Available for different amount of times).
Haven was available on the Roku Channel and others for quite a long time (great series). It will likely return in the future (no guarantees though). I was not aware it was also on the Acorn Channel during this time.
It is never really indicated how long a particular series or movie will be available when offered for free on any of the channels/apps. Depends how long the licensing agreement is for (and these are not revealed, for some reason.)
You can add Haven to your "My Feed" feature on the Home Screen of your Roku device, and should alert you when episodes become free again.