After Effects/Adobe Media Encoder Sound Effects Not Playing

Hello!

After adding sound effects to a video project in After Effects, I have no problem hearing all of the sounds just fine. The problem is that only some of the sound effects are playing once the file is converted to the final MP4. I assume this is an issue in AME and not AE since they play fine in AE. What could be causing this problem and how do I go about fixing this??? Please help! Thank you in advance!