Oil leak D5 185PS

Hello, has someone ever had a problem with oil leaks at the D5? Here’s a picture where you can see the spot. It seems to be below the oil filler. Near where the plastic valve goes into the block. Was also already in the workshop where my suspicion of valve cover seal was not confirmed. He had cleaned everything a little, and asked me to continue driving until there is something to see again. If someone knows this problem would be I’m grateful for tips.