SAMBA CIFS: Authentication for user [various logins] has FAILED

I was examining the log for my My Cloud Mirror looking for clues about why it sometimes shuts down and cannot be accessed from any device until I power-cycle it. That’s when I noticed gobs of these messages in the log. The [various logins] may have the email of my Microsoft account or one of several usernames I have for the different PCs, or “guest.” The messages can be generated every 5-10 minutes sometimes when I am not actively using the PC. I have three Windows PCs (work, laptop, and desktop) from which I access the WD MyCloud. Two of them have the Public directory mapped to a drive letter. From some other postings here I understand that these authentication attempts may be something Windows is doing in the background.

My question is whether it matters? Are these authentication failures actually affecting my ability to use the drive? The fixes I have read about here, but couldn’t really follow due to my limited understanding of networks shares, windows accounts, etc., seem rather complicated and if I have these failures occurring with multiple user names, would the fix have to be applied to each one individually? What would be wonderful would be a plain language explanation of what’s going on and if it matters to most users. Thanks.