Any idea why I keep getting this alert message (see attachment)…

Well the image begs the question are you trying to change or delete that .docx file ?
No, this alert occurs on its own when just opening the file…it seems to happen with most docx files…very perplexing!
The biggest issue for me is I don’t use a mac, so my Windows installation will differ.
I don’t use the docx file format and whilst I have the Ransomware shield enabled pretty much the default settings and it is set to Smart and Choose File Types manually. I can’t recall ever having alerts like this. The other difference is I’m not using Avast One but Avast Antivirus Free, so the interface differs as does the configuration (why I stuck with Avast Antivirus Free for Windows).
Looking again at your image the action that is accessing the file and triggering the warning appears to be ‘contentlinkingd’ the bit at the end of the string.
Is this file linked to something to check for changes ?
Nothing is being changed on these files upon opening (or at least it is not obvious). Perhaps Avast One just doesn’t like Microsoft files due to their history of insecurity! When I do a complete Scan, no issue show up so I’ll just ignore this glitch for now, and let’s consider this thread put to bed;)