Character is missing when receiving message on a topic

[ajinkyaw]

Hi . i am using sim800A module with arduino mega 2560.
I am trying to receive the following message string on the device.
{"device_id":"a3k4563b9az","request_id":"744745433","status":"TRUE"}

however i am receiving the string as
{"device_id":"akkadbakkad","request_id:"744745433","status":"TRUE"}
(a double quote after request_id is missing.) whatever character i write on that position is not being received and skipped.
I am using tinygsm lib. Now after trying everything from the internet now i am raising an issue here.

kindly please guide what can be done to resolve this issue.