Try putting the initial ‘make changes to thing’ action in a custom trigger, so the webhook is recieved by backend workflow, the first action is to trigger the custom trigger to make changes to thing, then your second action is to schedule the other backend workflow…custom triggers will ensure your make changes to thing action is complete before the initial series moves to step 2…also for step 2 in order to ensure it runs when it should try utilizing the ‘return data’ function and just simply return from the custom trigger the ‘thing to change’ and for step 2 in initial series, use the returned data as reference for parameters in the schedule backend workflow that is the step 2.