If you are finding that calc is putting garbage numbers in an cell with a reference to an external sheet, check and see if it’s looking in the external calc doc at the right sheet. I have a column of cells in a document that have references like this:
=‘file:///home/wsanders/portfolio-quarterly-yields.ods’#$Sheet3.J29
=‘file:///home/wsanders/portfolio-quarterly-yields.ods’#$Sheet3.J30
=‘file:///home/wsanders/portfolio-quarterly-yields.ods’#$Sheet3.J31
etc
The values that get filled in are actually from portfolio-quarterly-yields.ods’#$Sheet1.J29. portfolio-quarterly-yields.ods’#$Sheet1.J30. etc, all the way down the column.
This doesn’t always happen, and never happens when the external document is open or has been previosly open on the desktop.