Hi,
So just a quick update.
We can reproduce both issues here.
Issue 1) DR won't render an animation after the 1st frame - We have a fix for this in the pipeline which is currently in testing. Please bare with us :)
Issue 2) Enabling DR after the render has started, officially this behaviour was never supported and worked kind of by accident.
The reason this no longer works is due to some other bugfixes in DR, which fixed some crashes. We have added an error message to state that this is no longer supported.
I hope this information helps.
Thanks,
Rowan