So here is the whole story:
It was not really a plugin issues, meaning the plugin wasn’t malfunctioning, but
I did a (quite) stupid thing:
-the auto levelling plug I used was too hot at the output, it showed the outup gain in LKFS and in TP, I was in a rush and tired and I somehow overlooked the warning sings
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used also for metering a VU-meter plug after the auto leveller
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but instead of reducing the output gain on the auto leveller plug
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I dialed down the signal with VU-meter plug and went on from there
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I somehow ignored I was at 0 (ZERO) LKFS on the auto-leveller output 
But interestingly enough, while I did what I did in WL, everything / the playback sounded fine no issues no harshness
It only became apparent after the final export happened
I also later did comparisons, playback vs render
Thats where I’m a little baffled
Seems like WL was able to compensate it somehow in the playback, but export…
For troubleshooting, I did a test-export of the track with auto-leveller only, then
I saw the mess it was creating and knew from there came the harshness, because of my settings in there…
So finally, solution was that I reset the gain control on vu-meter and used it just as a metering tool only, while dialing down the output on the auto-leveller plug, ok I could have used the TP display in the leveller as well, but sometimes… 
But, afterall and lucky enough, I did not had to change that much in the rest of the chain after that
Also a friend of mine hinted me to check plug ins in the chain
After the correction the Export was super fine
But still, why wasnt it audible during the process only after export?
Thanks again
