I’m really sorry but without having the bike in hands it’s always very hard to find issues…
Do you ride during winter?
I hope we can find help near you, but that may take some time…
As mentioned before, no problem to send you one of my kits.
Would be just a problem if it doesn’t help…
I’d change the complete rear parts group including insert and acrylic washer between the tubes.
Unfortunately the inserts are not in stock here and we’d have to order them.
Please find a few additional infos at your malbox 