I’m a little confused between your description and your screenshot… Uploading your .rp file here would be a big help… You may have a small and/or unintended bug in your interaction code, or you may have some bigger issues going on …hard to tell without seeing the .rp file itself.
You say the “now” line can be dragged, and presumably the Dragged event moves “This” --itself, the “now” line. I would expect as it moves it would enable/disable the blocks behind it. But your screenshot does not indicate which widget is selected–the line or one of the blocks. I would imagine it is the “now” line because that is what would move when it gets dragged, and you don’t mention anything about the blocks moving. However, it appears it is one of the blocks because of the “Disable This” action–and you don’t mention anything about disabling the marker line. So how does this work? …Maybe the Dragged event “fake moves” the blocks by (0, 0) …or fires their Moved event–, then each block tests itself against the y-location of the line? That approach should work, but may get buggy if you have a lot of blocks as it could kind of overwhelm the processor. Keep in mind, the Dragged and Moved events would get fired every time the Marker line moves–even one pixel. (Try viewing the Trace in the Interaction Console [click the lightning bolt icon in the upper-right of the prototype player in the browser] and drag the line just a little bit–see how many times the Dragged event gets fired!) …How many blocks is too many depends on your system resources.
It does–or at least it should–and it does so for me. I’ve done similar things many times, and properties of a dynamic panel, like it’s y-position, are available in real-time in conditional cases. I demonstrate this in the prototype below. If your setup is different, or I’ve misunderstood your issue, please reply, explain further, and upload your .rp file, please.
dragged widget position.rp (58.8 KB)