Player movement

Hi, I am developing a small project. I am attaching a video to show the problem. While I am moving the character front, side, back, etc, everything works fine. While I am moving the character with the rifle aiming, the movement is working fine. But when I start to move the character, after while having the same rifle at the back of the character, it is responding in a strange way. The character is moving is a diagonal direction for some reason. I am not sure what is the mistake I did. This was working fine until 2 days back. I messed up with something that caused this. I tried to troubleshoot but could not find the reason on my own. Please some
one help me.

There is one other problem which I am facing recently is, after I dropped the weapon, it jumps to different heights. This was also not happening 2 days back. May there will be one and same reason that causes these 2 issues. Please can anyone help me, I appreciate it a lot.