Mail merge prints all records blank except last one

I use mail merge twice a year. Unfortunately, my memory doesn’t last long enough to do it two years in a row
without undue stress and gnashing of teeth … Not to mention profanity.

I have a Calc worksheet with 124 data rows. Deleted all columns not needed.

I have a template envelope file that I’ve used several years.

Unregistered all previous data sources.

Went step by step several times, both using microsoft format and open document.

When I print to a file, the result is 124 records. 123 are blank and the 124th one
contains the correct data for the last row in my spreadsheet.

I’m “mature” and it’s toward the end of the day = maybe it’ll work in the morning.

Note this is the 3rd year to do this and eventually I’ve gotten it to work before.
However, going step-by-step has always worked in the past.

Did I forget to mention it? Please Help!

RESOLVED (not the same as solved)

I started with a new envelope and it ran like a champ!

Found a clue.
Even though I thought I deleted all existing database connections to my template,
I suspect there is one not showing there that messes up my merge.
NOT solved. but trying to understand why that connection exists when I deleted all of them.