not a good sign for the gpu , if you can , test it in another computer
you can try to underclock/undervolt to see if anything is different
check if previous drivers change something
check temperatures of the gpu
in the forum somebody posted the same picture as you , with the same artefact and a rx 570 ... maybe it's a driver problem or a conflict with another driver because having exactly the same artefacts would be a weird coincidence , or you re the same guy that already posted with another nickname ...