When configuring batch options, users can choose how to handle potential constituent matches. If you de-select the "Match records" option and select "Possible Matches" so that records are identified as a possible match if the match percentage is between 50%-100%, when the batch is saved, it will automatically assign a matched constituent instead of setting it as a "possible match."
If "Match records" is left selected, the possible matches will show up correctly.
This problem also occurs if both options are de-selected.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.