Without seeing the full report I can't be sure why you are seeing that, but it should not have imported the same hand twice because a hand with the same hand number and site will be rejected as a duplicate.
Please attach a screenshot of the full PT4 window to a
Support Ticket so that we can see what might be happening.
You could also try resetting the report to defaults as I suspect that will remove the problem.
Right click > Configure Report, then click Restore to Default.
This will remove any stats that you have added to the report though, so if it is a heavily customised report you may want to just view a different report instead first to check whether the same issue occurs there.