Keep Planned Work Hours while increasing duration (start/due date) from GANTT view

Keep Planned Work Hours while increasing duration (start/due date) from GANTT view

Hello,
I'm mainly using Projects to manage my personal projects and avoid missing deadlines.

I usually run several projects in parallel and I apply this process:
  1. I start by creating some task lists containing tasks for each project
  2. for each task, I set an amount of Work Hours
  3. then I move to GANTT view and I visually organize each task Start date and Due Date. I do the following:
    1. I click on the start date
    2. I increase task duration by dragging the blue bar (see screenshot attached)
  4. then I move to Workload view in order to see if workload fits the available working time
I'm a bit confused about step 3.

Imagine this situation where I want to split the workload of a 14 hours task evenly in a time span of 3 days:

Working Hours per Day = 8
Task workload (Planned Work Hours) = 14 hours 
Task start date = 14th of April 2022
Task due date = 16th of April 2022

Problem is: if i change the start/due date from the GANTT Chart, then Planned Work Hours are increased to 24 hours.

Is there a way to keep the Work Hours locked to the initial value while increasing duration?

Thank you