S2721DGFA, horizontal lines across whole screen

Hi,

I received my Dell S2721DGFA monitor about a week ago. Today after gaming (on PS5) all of a sudden there were these horizontal line across the whole screen of varying color and at random. I could still see the content, but these line were present everywhere. The problem persisted despite: changing to another HDMI port, using a different cable, using a different HDMI source (PS5 and two other laptops). There was no incident that preceded or occurred with the appearance of these lines. When the screen is without an input, I do not see these lines. I also ran the self-diagnostic test (assessing different colors on the screen) and only faintly saw them with the grey color.

Please assist. Photo below.