RM Pending Wait did not clear

Here is rule in question:

And here is a correspondent log:

At 08:08:23 Stove was turned ON, rule was triggered and created a pending 3 hours wait:

At 08:15;25 Stove was turned OFF, rule re-triggered. At this run all actions were skipped
(this is exactly what should happen). At this time the PENDIG wait must be cleared but it
was not (still seems to be scheduled).

Even if I re-run rule manually this PENDING wait still seem to be active.

Is is right rule behavior?

In a past I did not watch any rules for these PEDING waits so, I have no idea is this
normal or not (I hope, this is normal behavior.)

Yes this is normal. You need a "cancel rule timers" action somewhere. I think it's under set variables? Going from memory here.

Oh, and you also need to edit the action with the timer and toggle the cancelable option to on.

All what you said is applicable to older "DELAY" statements.
Lates (newest) "Wait for Event -> Elapsed Time" statements should be self cancelable.
Is not it?

Yes, but I was under the impression from looking at the rule that the 3 hour pending wait was for the timeout.

Yes, this is "Wait for Expression" statement with Timeout protection.
This is also must be re-triggerable (i.e. should be reset on each sequential Trigger event).