I had a poptop fitted by Streamline. It felt like it was the first time they had seen a 6.1 arial, and didn’t want to relocate it themselves. Instead, they got a slightly deeper roof and trimmed it down as low as they could but leaving the arial in the OEM position.
I wasn’t impressed with Streamline, their website is a mess, the factory is disorganised, and they filled the van with swarf cutting the hole. There was swarf in some of the connectors so the rear view camera didn’t work. It wouldn’t surprise me if they got swarf in some of your cab roof cabling.
I don’t have any radio issues, but I think that fin is the SOS; DAB is in the wing mirror.