Your English is better than most of the native speakers, congratulations! :-)

First problem: in our general experience, the Dovo from factory razors aren't really sharp enough to give a good shave. They are sharp, but not shaving sharp. The most likely effect of this is that the blade will pull on your beard, which will lead to you putting extra pressure on the blade. This will lead to razor burn, which is when you shave off a sliver of skin, and is a painful red area on your face.

A fully sharp razor needs almost no pressure at all, and should glide over your face. You will need more than one pass to remove all hairs.

A badger brush with palmolive creme is just fine.

One possibility also is that poor strop technique could dull the razor. You need to keep the hanging strop very taut, and keep the razor exactly flat on the strop with almost no pressure. But what you describe is likely to be just the result of the factory edge - see the sticky at the top of this section.

Your best option is to send your razor to one of our expert honers for checking and sharpening; that way you can be sure that it is a sharp as is can be. Both Bruno and LX_Emergency are close to you (in Europe, that is; I think both are in Belgium).