Left AirPod Pro Cracking sound

Hello. Three months ago I returned my first pair of AirPods Pro at my local Walmart due to a crackly sound that I began to hear in my right AirPods Pro. I got a second pair a few days after I returned my first pair and yesterday (April 27, 2020) my left AirPods Pro started a cracking when I am in noise canceling or transparency modes. I connected and reconnected them from my Apple devices. The softwares I interact with are iOS 12.4.6 , iOS/iPadOS 13.4.1 and macOS 10.15.4 Catalina. I have checked my AirPods Pro firmware version and it is 2B588. Do you know what the problem is? Thank you. Stay safe!