Oozing / stringing issue

I'm printing on a V core 3 with PETG. I mostly go oozing problem when i'm printing. I tried reducing the heat from 235° to 225°C. I also increased the speed of the fan and retractation distance from 0.5 mm to 2mm. I also find an option in Prusaslicer to "wash during retractation" but i tried and didn't see any changes. With different PETG filament I got the same problem. Any ideas what it could be ?