2021 Citroen Relay radio problem

[Ryan1947]

My Citroen Relay van radio has a problem with signal strength across all three radio waves bands, this includes Dab, FM and Am. On Am and FM I literally just get static, on Dab I get a few stations that frequently lose signal when I drive around. I have unplugged and pluged back in the connections at the back of the radio, I have also replaced the antenna with a new one but still no change. I'm thinking that because it's across all three wavebands that its unlikely to be the headunit itself, maybe someone could point me in the right direction to what's likely the problem. Am I right in thinking that to get to the underside of the antenna I need to remove the headlining. My thinking is that I should check all the connections at the base of the antenna inside the van.