You'll need to explain the exact steps and the options you have selected for these imports. They really shouldn't "override the data" from a previous import unless very specific options have been taken.
But each import produces a brand new found set. Pre-existing records are automatically omitted from that found set. But they are still in the table and you can bring them up by performing a find or selecting "Show All Records" from the records menu.
Thank you so much. I did go to "See All Records" and found that all worksheets are present in Filemaker Pro. Am trying to relearn this software on my own and it does help to have a second pair of eyes.
Hope your day goes well.