It's an 11 year old TV even if you bought yours more recently so more than likely iPlayer needs newer processing hardware now which no firmware update (if Samsung could be bothered with a set that old) would fix. You'd need a streaming device to send iPlayer from your phone or tablet to the TV instead. I use a Chromecast with mine but iPlayer is on Fire Stick too. EDIT - I did some digging, the last firmware update for the TV was in 2015. In 2019 there was a major upgrade to iPlayer that needed another upgrade on Samsung products. So it's entirely feasible the same has happened again 3 years down the line.
