EXCEL Crashes while opening External Data connections workbook

Yes, this is a known issue Excel Version 16.0.19231.20216, may consider below if automatic updates suspension is not an option:

1.    Modify the COM Add-in behavior:
o    If possible, delay or defer the external data connection until after the workbook is fully loaded.
o    Consider wrapping the connection logic in error handling to catch and log exceptions before Excel crashes.
2.    Use Office Insider or Beta Channels:
o    Sometimes newer builds in the Insider or Beta channels contain fixes for recent regressions.
o    You can switch to a different update channel using the Office Deployment Tool or Group Policy.