Auto Import intermittently fails to import just-captured images even though the files are fine

First of all, here's my setup. Raw images are shot using a Canon EOS 60D and Canon EOS Utility 2 into a folder called "incoming" which sits at the top level of my Windows user's Pictures folder. Lightroom Classic is then configured to move these to a folder called Auto Imported Photos, located within at the top level of my user's OneDrive Pictures folder. 

Most of the time, these images are imported into Lightroom correctly. However, perhaps one in every 10-20 shots or so are imported but then *instantly* given a "photo is missing" flag, even though the file in question exists on the hard drive exactly where Lightroom says it is, and is non-corrupted.

Although it's only one in 10-20 shots or so that are affected, the problem sometimes happens much more frequently. For example, I just shot the same image four times in a row, and all four attempts to shoot the image were failures, leaving four stray files in the folder Lightroom imported them to and four half-imported-but-unusable entries in my Lightroom catalog.

If I attempt to locate the "missing" (but not actually missing) files by clicking on the "photo is missing" flag and selecting the image that failed to import, I'm told that the file is "associated with another photo in the catalog." If I click "show in library", it shows the thumbnail with the "image is missing" flag, indicating that it can't be imported because it is being blocked by... itself?! If I then right-click and select "go to folder in library", it takes me back to my Auto Imported Photos folder.

If I remove the selected images from Lightroom, I can then browse to the Auto Imported Photos folder and reimport the images that failed to auto import correctly. Occasionally, they'll import successfully on the second attempt, but more often than not they'll fail to import again. (And sure enough, with my example today, all four images imported with the same incorrect indication that they're missing when they aren't.)

The images in question open just fine in Adobe Bridge, Photoshop and Camera Raw without doing anything, it's only Lightroom that refuses point blank to touch them. Most of the time, I have no choice except to waste my time shooting and deleting photos over and over until one of them, for whatever reason, sticks and is accepted by Lightroom.

Anyone else found a solution to this behavior?