DJI 4 Pro - sorted the issue - we switched batteries to new carbon based batteries - flight time at hover, which is only one of our test criteria, is now 58 minutes 14 seconds best case and 56 minutes 19 seconds worst case scenario - we will do...
The 15 mins you mentioned first sounds abnormal for the Mavic 4 pro.
Your flight data will probably find the reason for it.
Can you give a little explanation for your new "carbon based batteries" ?