Transform Map ignoring updates?

[JP-ODU]

I'm trying to do a very simple import to a table: I have an Excel with IDs and addresses, I load the data, I create a transform map that maps ID:ID and Address:Address, I set coalesce on ID to true. I run the transform map... and over 8,000 records are ignored.

I exported the table with the blank addresses and created a new Excel file to import, making sure that ID and address are all filled in. I do the import and transform again, and the updates are still ignored... I should have a flawless 1:1 relationship for these. They should all be updates, no ignores.

I don't understand why this is happening. How do I trouble shoot a transform map ignoring a large number of updates that it should be making?

[LouisG]

Thanks for getting back to me, JP.

This import originally brought over 14,000 empty records on a custom table, and I ended up clearing all those records off the custom table, but since then, I haven't been able to get it to insert records. 

I'm still receiving the warning in my log, so I'm still not sure what's going on but I'll keep looking. Additionally, of those 14k records that were made during the bad test, it generated 1 user record on both the sys_user and the custom table, and I have since set that user record to "Inactive".

***Update: I found that when I reprocess the Transform after 0 inserts were made, it'll insert the 20 Test records the second time.

[JP-ODU]

Checking the import logs, I see there's one warning: "Security restricted: Refusing to process UI page script without a valid CSRF token" but I'm not sure what that means or how to proceed?