Specific condition;
Pulsing when brakes are cold and after running some time before using brakes.
After brake heating, the pulsing would subside each time, then return again.
.
The proven cause in this case was 'some' over tightened lug nuts on one wheel.
.
What was happening:
The over tighened lugs distorted the bearing Hub on a 4x4.
This put a cold 'wave' in the disc.
When braking heated the disc it straightened out to a large degree but returned each time when cold.
.
How over tighteneing happened;
A shop replaced the front Hub bearing assembly and over tightened the lug nuts using an impact wrench without paying attention to the torque being applied.
.
This was found by noteing the effort to remove all the lug nuts centered on 3 very tight and 2 just tight.
Only thing done was replace the wheel back on and torquing up the nuts to some evenness and doing a test drive over two days showing the issue was gone.
.
Bottom line is not to get on the lug wrench and go wild tighening them until they won't go any more or to uneveness.
.
There is a torque spec based on the hub, wheel design and material used in them.
This is not the cause of every in case but was different in how it acted being temperature sensitive.
Make sure them lug nuts are not over torqued and done with reasonable eveness.
Watch especially after inspections and when work is done.
Good luck.