Please follow the technote mentioned below to replace the tape device , It might help -
How to update NetBackup for a replaced tape drive without deleting and re-adding the drive - https://support.symantec.com/en_US/article.TECH34296.html
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Hi , Please review the dpdbm logs for errors and paste the output here too.
Also please confirm the value of Client_Port_Window registry, It should be 0 0.