High-side pMOSFET does not switch to ground
When the P-MOSFET is off, it runs no more current into VLED.  It is possible that the input of the LED does not provide a pull-down path, and the drain voltage just keeps floating above ground.  You &quot;fixed&quot; this with the pull-down array that discharges C62 and C63, but such does not seem necessary to operate VLED.

The negative peak might be due to the inductor L3.  When the current through L3 collapses, the inductor reacts with a voltage spike of opposite polarity.  Can you try adding a flyback diode across L3 (me not knowing its purpose to begin with)?