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

Same issue happening to me. Shared folder in OneDrive, selected Anyone with the link can edit, unchecked allow editing and put an expiration date to 6/1/2021. This morning received 5 email from users outside our organization, all of them saying the link is asking them to login. After reading this thread, I see how cached credentials in their browsers could cause an issue since it is supposed to be accessed "anonymously". Having said that, how do we fix this? asking external users to use Incognito mode in browsers, although it works, does not seem to be the most elegant solution, specially when we are talking about hundreds of users accessing these folders. I don't want to suggest my staff to use Dropdbox, please help find a solution!