Thanks Maxim

Actually null character is not being generated by Client .

We are using below module to validate the tokens
https://github.com/kaltura/nginx-akamai-token-validate-module

This is being caused by akamai_token_validate_strip_token directive which strips the token and forwards request to upstream server.

While striping the token and passing the remaining request to upstream stream its appending null character at the end.
If there is no any additional query param in request apart from token , then there is no issue in handling.

http://10.49.120.61/folder/Test.m3u8?token=st=1593095161~exp=1593112361~acl=/*~hmac=60d9c29a65d837b203225318d1c69e205037580a08bf4417d4a1e237e5a2f5b6&uid=abc123

Request passed to upstream is as below which is causing problem

GET /folder/Test.m3u8?uid=abc123\x00