Tiny bulges on wallcoverings made of paper and not vlies/vinyl

I bought several rolls of rather expensive wallcoverings made of paper covered with acryl. The wall was already prepared with several layers of different kinds of pop and putty with primer. (Trying to translate pop/putty/primer from Russian into English took a lot of effort and I am still not sure if it’s correct.) The prepared wall generally looked smooth to the eye or touch. But after the workers hanged the wallcovering on the wall they appeared covered with tiny bulges all over. They were not visible when the wallcoverings were wet. But when they became dry the bulges appeared. They are very small in size, so tiny that I can’t see them from about 1 meter distance. They also don’t show up on the photos from my phone unless a bring it very closely to the wall and try to find a good angle. They look like tiny specks of dust trapped under the cover. It’s almost like my wall has acne and it saddens me greatly.

Here is photo:

The photo shows only several of them but in reality there are a lot. They look rather ugly if you come closer to the wall and look.

The workers claim that because they are made of thin paper and not vlies or vinyl putting them up without these is impossible because all random dust is visible. Workers experienced with wallcoverings in Russia all say that I need to always buy vlies or vinyl and never paper because otherwise high quality is not possible. My question is if it is possible to hang them better without these annoying things? Who is to blame here? Lack of skill or the wallcoverings of paper are indeed not good in general? And why did they appear at all? Is it dust, glue or uneven wall?