Need your thoughts

Hello, my baby is almost 5months now, he grabs anything and puts it in his mouth. While I know that it is normal, the problem is he gets really upset after a few minutes. Upset to the point that his face gets really red, cries and screams out loud as if he’s really angry. I am just wondering if any of you experienced the same thing? And how did you address it? I understand mouthing is important in his development but I am just really not sure why is getting upset. Is there something I am missing? Thank you. ☺️ #firstbaby