Samsung MM-A900 / SPH-A900 / Ace

For some reason, I am starting to get poor reception. My first A900 was working fine but I sent it it back because I thought that something was wrong with it. There wasn't anything wrong but it was still replaced. I love my phone but now it seems as the reception is not as good as my first phone. Can someone help me??? 😢 (Also, I did do a software update about two days ago but don't let this bias your comment..just for your information)

Yogi