A few days ago I asked an engineer to replace my existing Zone 1 dish with a Zone 2 dish. Unfortunately this has now led to a dramatic decrease in signal quality, whereas previously my assumption was that it will either improve slightly or stay about the same. Is there any possible reason for this?

For comparison my Zone 1 dish would show SNR at approximately 82%, whereas my new Zone 2 dish is showing SNR at approximately 64%. These readings are about an hour apart where weather conditions don't seem to have changed using the same hardware.

My biggest concern is that this will now lead to a broken or distorted picture on a regular basis when it rains whereas previously I only use to get this when there was heavy rain and lightning