Problem with linked files causing files to open very slowly?

[au2010]

I use a number of linked Excel workbooks. Sometimes, files which are not particularly large seem to take an extraordinarily long time (several minutes) to open, and when this happens, it's accompanied by a message in the lower right part of the Excel window that says "LINKING: (linked file name.xls)" and then a status bar which fills up very slowly. See the attached screen shot.

Does anyone know what causes this to happen? I cannot seem to discern an real pattern here - it seems to happen almost at random, but maybe there's something I'm missing.

Here's some additional information that could be relevant:

1) When it happens, the "LINKING" message only lists the name of one linked file, even if the workbook I am opening has links to more than one other workbook.
2) It doesn't seem to be consistent even for the same file - sometimes when I open a given workbook, it gives me the "LINKING" message - but other times it doesn't when for the same file.
3) Sometimes it happens when opening an .xlsx file that has links to an .xls file - could that possibly be a factor?
4) Version: Excel 2016, Office Professional Plus 2016
5) The workbooks are all stored on a remote network drive, not on my local hard drive.

Thank you!