I would say the front fork oil is being airated. It happens alot to oil in sumps of superbikes (hence sump baffles).

This could be caused by you not bleeding them right and the dampers still having air in them. Once you ride the bike the air is pumped out and the oil level drops.. hence you get little or very light damping after a few miles of road work.

Or your using crap oil and its turning to piss when its getting hot and your damping is going out the window.
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If I have to take the carbs off once more...