Sometimes when making changes and getting this in a better position there can be some discomfort.
Starting to use muscles to maintain positions which were not used in the past.
As you continue to work with the new positions this should improve.
Are you addressing the soft tissue above and below where you see the issue?

A couple episodes to check out.
They helps to improve range and mobilize with movement.
Episode 87: Hip Impingement 2: Band Variation
Episode 161: Hip Impingement: AIS

You’ll want to take breaks while sitting for extended periods of time.
Optimize your sitting position for when you must be sitting.
A couple episodes which address sitting position.

Start transitioning to a standing work space. This allows for movement through out the day which helps the negative impact of sitting.
Why Sitting Wrecks Your Mad Hip Action

Episode 170: Death by desk? More powerful typing
Episode 251: High Skilled Sitting/Abdominal Bracing