Hi @JohnStraumannPA ,
There are the following possibilities:
1\ Delay or caching issues
2\ column name caused
You could try to create a column in your excel file. Its column name is the custom column name in dataverse.
// In my test I fixed the problem by modifying the column name in excel.
But I can't be sure that the problem is caused by the column name, it could be the delay.
Besides, you could use a easier way to do it. (I prefer this method.)
Best Regards,
Wearsky