I am having an import problem with an upgraded to 12 solution that is one of those 'nightmares'. The original developer was replaced by a second developer, etc. Now it is mine to suffer with.
So, here's the import problem. Note that I have tried most everything in my 25 year old bag of tricks.
Find a selection of records in one table
Import that selection into a second table in the same file.
The selection was found using a go to related record.
Next attempt was vial a standard enter find mode....set fields....perform find
Either method shows the same set of 6 or so records in that table.
Switch to the other layout and doing a find imports 85,000 records, the entire file.