GPS works in accessory mode only
 

Has anyone had the issue of only one or two satellites when the engine is running, but when the engine is cut off and the car is in accessory mode it jumps to 8-9 satellites? Acura can’t figure it out and I’m wondering if anyone has had this experience. My marine industry experience in electronics installation would point me to the antenna needing copper shielding to block electromagnetic interference, but not sure if the nav unit itself needs shielding, replacing or a faulty antenna. Any help is appreciated, if anyone has replaced the antenna please point me in the direction of its location and how to get to it. The Acura service guy told me it’s the shark fin but I’ve read that’s xm only and the gps antenna is under the dash? Thanks!!