Finally I replaced all the propellers. My MA2 hit small tree branches while I'm adjusting it to the right angle to snap a photo. It didn't crash. Since then I noticed that the noise level increased. I didn't change the propellers immediately until one day I obviously saw during landing process the MA2 not stable. It seem to be swinging a bit. One of the propeller has scratched mark and others still in good condition. I decided to change all the propellers and the result is satisfactory. I believe that the noise not so loud as before after hitting the tree branches  and no weird movement during landing.

Good to know - always best to replace the props after a collision

Hello there DJIMNYD. I am sorry that your DJI mavic Air 2 hit a small tree branch before and it is good to know that you have changed the propellers of the said drone. If you have any issue or concerns with your DJI Mavic Air 2 or with DJI. Please feel free to post it here at DJI Forum. We are here to help and support you. Have a safe and a happy flying always.

Best to check the props when you open then before each flight.