I have a workaround that works for me. Hopefully someone else will benefit too.
I have Sophos Home too and cannot see any logs or events that would indicate that there are issues with it and the writing of the updates into the executables etc.
What I can see is when I leave the Star Wars Sqaudrons folder open, I see the DIP_STAGED files and other files that appear to be the actual patches before they are integrated into the DIP_STAGED file. Once I receive the first retry error in Origin, I go into the folder and delete any original file that now has a DIP_STAGED equivilent file. I then rename that file and remove the DIP_STAGED. I do this for the entire folder structure where the game is installed (not the program files etc).
Once I do this, I click the retry and it will resume the patching and probably stop at around 98% with yet another retry error. I go through the folder structure again looking for DIP_STAGED and delete originals and rename the files.
I often find that the touchup.dat and cleanup.dat originals are not present but their DIP_STAGED files are, I think this is part of the problem but who knows.
Anyway, after multiple retries, and lots of renaming, I get the update to finalise. Once this is done, I run a repair and can run the game again.