Hello Arth Shah,
Please try the newest KSDK2.2_FRDM-KL25 usb_cdc code.
You can download KSDK2.2_FRDM-KL25 from this link:
Welcome to MCUXpresso | MCUXpresso Config Tools
SDK Builder, board choose FRDM-KL25, then generate the code, and download it.
I have test it on my side, it works ok.

Please try it at first!
Any question, just let me know!
Have a great day,
Kerry
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