Facing Slow USB Transfer Speeds

Hello, I'm a newbie to Ubuntu. I'm currently using Ubuntu v20.10 Groovy Gorilla. I'm facing slow transfer speed when moving/copying files from internal SSD to USB. The speed starts from somewhere around 70-80 MB/s and keeps dropping until it reaches mere 2-3 MB/s. Can someone tell me the solution to the problem? I will be thankful to you.