Understanding Excel File Operations in VB.NET Programs

I'm running a VB.NET program on my PC and importing Excel files.
The program, which takes about 40 minutes until the middle of November, will take about 3 hours.
The Excel file to be imported is edited in various versions of Office (2013, 2016, 2019).

I checked the log and found that it took 3-10 seconds to open the Excel file and
It seems that it takes a long time to process because of that's why.
When I checked the event log of the PC running the VB.NET program, I found that
Excel.exe with version "16.0.5083.1000" encountered an anomaly.

There is probably an abnormality in Excel.exe, so
I think it's taking time to open the Excel file.
What do you think is the cause of the abnormality in Excel.exe?

The environment of the running machine is as follows:
Operating System: Windows 10 (64 Bit)
Office:Office 2016