Please ensure you are using the latest version which is 220.127.116.11. Try other reports to see if the problem is the same, if so, it's an issue with your data entry, if not, it could be a bug in the specific report you are running. Try the Split Series...Jeppesen Style report and see if approaches show there. If so, tell me the exact report you are viewing and whether or not it's a custom template. If it is a custom template, ensure the data field is defined for the column of interest.
If you need further support, please submit a support ticket attaching a backup of your Logbook Pro data file (File..Archive..Backup).
Its version 18.104.22.168. Its the Reports/Flight Log/MGOEnt Leather Binder Solutions/MGOEnt Old World & Premier Leather Flight Log report. The strange thing is when the report "prints" to the screen approaches show accurately. When I send the report to the printer for a hard copy the approach column in blank.
If you export the report to PDF, do the approaches show? Can you print from Adobe Acrobat Reader? It sounds like it may be an issue with your printer if what you say above is true and is outside that of Logbook Pro support unfortunately.
I ran the same report, printed it, and had no problems seeing the approach data. So I'm unable to repro the issue here.