Quest 2 signal problems

I have finaly got my Quest 2 fitted and working. I had it quite low on the bars so the unit sat about 2 inches above the crossbar. It worked but seemed to lose sat signal every couple of minutes. Some times it would be down for 20-30 minutes. Then I tried it in the Pajero and it worked great. No signal prolems and very stable. I tried moving the ram mount on bike so the unit sat higher on the bars (about 5 inches above crossbar) and it now works great. Just wondering if there is some sort of interference from the bike (GSA 1150) that affects the Quest?
Also, do atmospheric conditions affect the strength of the satellite signals?

Cheers

The two Quest 2's I've had didn't like anything in the way of the view of the sky...the first one would lose lock the second I went under an overhanging tree!