Assuming your Cache-A works with other LTFS volumes, this tape is bad. If all your LTFS tapes do this then it's the system but I expect this is the only one. From your terminal output, it looks like the tape is empty in addition to not mounting. Something damaged it beyond the ability of the existing LTFS tape tools at the time to fix it. My only thought that might help would be to try to repair it with newer LTFS software (i.e. a current copy of PreRoll Post or Yo Yadda).
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