Files shared with Anyone sometimes prompt users to request acccess to the file

Did anyone ever figure out what was causing this behavior? I realize this thread is a year-plus old at this point, but we are experiencing this same issue in our tenant. We have published links to OneDrive files on our website using "anyone with the link" permissions. Occasionally, a user will click a link to one of those files and immediately be prompted to request access. This generates an email to the Group owners asking us to approve or reject the request. The link in the automated email sometimes identifies the actual file in question, but other times the link incorrectly points to the root level of the Group. I have corresponded with enough of these users after the fact to verify that they were not trying to access the root folder - in every case, they clicked a link to a specific file via our website. First step on our end was to make sure that those links were correct. We have tested them in 'fresh' browsers and incognito windows. They work for us. There seems to be no logic to when the link will work properly and when it will display an access challenge. Here are a few scenarios that actually took place. All of these users clicked a valid link on our website as their first step:

1. User tried three times in a row to download a file. Each time, an automated email was generated. He ended up calling our Service Desk and finding a workaround that did not require the file, so it's unclear if he ever would have been able to download successfully. 
2. User successfully downloaded a file. She then came back a few days later and tried to download the same file using the exact same web link. This time she was prompted to request access. I contacted her the following day and asked her to try again, and the link worked.
3. User received an access request. I happened to see the automated email within a few minutes and reached out to her to get some more details. As part of troubleshooting, I had her try the link again, and it worked.
4. User received an access request, restarted her browser, and the link worked.

We haven't submitted a ticket for this yet because we can't find any way to reliably replicate the behavior. This is the first thread I've found that seems to describe the same issue, so I'm hoping someone has figured out how to make it go away and just didn't update the thread with their workaround :).