Melee Hits Aren't Registering?

Hello all,

I have been playing Halo since CE and am still continuing to play Halo 5. I love the game and all it has to offer, but lately I’ve been getting annoyed with one aspect. I play a lot of FFA and am placed in Onyx, and I tend to use my melee attacks quite often, but these past few days some haven’t been registering, causing me to miss and easy kill and then getting killed. I mean it doesn’t happen all the time, but it has happened enough to where it really ends up hurting me during gameplay. I’m not sure if it’s a connection issue or what, but my internet is usually very good. Basically what happens is I am in a gunfight, then go to melee someone, and my spartan does the animation, and I hear the sound of the punch, but the other guy who is usually one shot doesn’t die, and ends up killing me. Any ideas or feedback?

Thank you,