Your minimum hour value dynamic expression looks correct…have you made sure that the Start Time Pickers Value is not empty and that the condition is being me (ie: the dates are the same).
Use the debugger and the inspect tool to check on these values from the preview page.
Good idea using the debugger/inspect tool; I’m new to the platform and completely overlooked these so thank you.
It seems as though the check to evaluate whether the condition is true happens after an initial date has been set in the end date picker. Once a date has been set (which is not governed by the conditions of being >= the start time) I can then click back in the field to set a time which is adhering to the condition.
I’ve now opted for a completely different workaround (user sets the duration instead) but thank you for the help!