Levo 2020 shock does not hold its rebound setting

[Jeff McD]

So on the 2020 level S works rear shock I run 6 clicks of rebound dampening from full open/fast rebound. After a brief rough high speed downhill the setting will lose its place down to four clicks or even less and just starts getting too bouncy like a pogo stick. Anyone else notice this and is there a simple fix? I have tried tightening its very tiny Allen bolt on the red rebound adjuster knob but it is already very tight and has not loosened up. Any ideas? Going to be taken into LBS if need be.