iMac m1 24 inch black horizontal lines

I bought this iMac m1 18 months ago - OS automatically updated as usual and suddenly on start up I had black horizontal lines on the display. Took a screen grab and the lines do not show so I'm thinking it's a display issue.

Can the new Macs be this fragile? After having bought many Apple products in the past they all seemed more robust and lasted longer. Dented my confidence in making future purchases for sure.

any guidance appreciated