I wonder if the root cause is similar to your older thread about freezes in Opus with doc and PDF files. Maybe something that can affect both programs at different times (so Lxp's guess of antivirus might be correct).
We also had a report that NVidia Broadcast seemed to cause a problem when Word opens:
If the viewer pane is open then that might affect things, as Word's preview handler would be trying to open the file at the same time Word itself is opening it.
Have you checked what happens in File Explorer to see if the same happens there?