Helpful note:
Case -
1. PowerShell script creates >15k word.docx files from .csv file data and save to local folder synced to SharePoint document library.
2. Flow triggers when file is created in the SharePoint document library.
2.1 Flow creates the same file in different SharePoint site. (Always succeeded)
2.2 Flow moves the file created in (1) to a different folder in same SharePoint site.
The problem presented on (2.2) telling me the file was locked and Flow failed.
The problem was inconsistent with a few (not necessarily sequential) successful flow runs and many failed flow runs.
Implemented the solution found here with no real success. The solution works. But, only if the file ever becomes unlocked, causes long flow runs, excessive network load, and the need to 'manage' the instances where the flow times out without successfully moving the .docx file.
After many hours of failure and on the next morning, I closed Visual Studio, reopened to run as administrator, and ran the same script again.
EUREKA! 100% success rate.
Decided to comment here because, in all of my hours and hours of researching, not a single mention of such a simple step. Could be unique to my situation but worth a try for someone with similar issues.