u/CombinationMobile238

I have an APX7000xe that I use for public safety purposes running both vhf and uhf. I have always had transmission issues and was told by a dealer that it’s because I had the wrong antenna. I recently purchased a new one that I thought was the correct one however am still having issues. Power and everything works fine as confirmed by the dealer. The antenna I got is the one linked below. Could I be still using the wrong antenna or could it be a different problem.