smart caching doesnt autostart anymore?

Hi, in DR19b1 I activate "smart caching", get the red bar on top of a clip, and when I hit play, wherever it passes by, the bar becomes blue. BUT: if I do nothing and wait, it doesnt start (or continue) to get the rest done.
Yes, in project settings, I didnt change the 5 second starting time for enabled background caching...

regards
Mike

BTW: I just checked on a DR18.6 box, and here, the auto-caching starts perfectly.

another thing: right-clicking on a clip, I dont find the "reder cache clip source" -> ON to activate user caching... (I know, it also was gone in DR18.6, but how do I activate user cache rendering for a clip then???)

regards
Mike