I am a SP Administrator / Developer working for a fairly big organisation. We recently moved to the 2019 version and as a result of user complaints I have discovered that there seems to be a bug in document libraries. Note that all of what I am about to describe is in CLASSIC experience and within the team site (classic) template.
I have created a fresh document library within a test site collection to double check that the issue is not specific to the libraries where users have reported the problem. The setup where the bug happens is:
Management of content types is turned on
There is a multiple lines of text column titled "Comments" which does not allow unlimited length
There is a person column titled "Assigned person" which allows on user to be selected from the directory
And onto the bug itself, in the above scenario if the user attempts to save the properties for the document with text of more than 255 characters in the "Comments" field, which of course triggers a validation error asking the user to reduce the number of characters, the value in the "Assigned person" field vanishes. This happens even for documents that were already saved with a value e.g. it will delete the existing value and if user doesn't notice and then saves correctly, the value is gone!
Has anyone else encountered this issue before and if so, how did they fix it?