We had created specific field configurations for individual issue types, with the intent of making sure only the appropriate fields for each type were displayed when creating tickets.
Recently, it has come to light that we are getting different user experiences within our Jira instance, where some fields have suddenly vanished for users without warning. There does not seem to be a pattern to it, and it results in the affected users needing to switch off the "User request type fields" option, go to "Show fields" and re-add everything they need by using the checkboxes there to show fields that were never previously hidden.
This has only started happening in the past week or so, and it is not affecting all users at the same time.
We first noticed there was something unusual happening when trying to add a new custom field to a specific issue type screen, While the "Find my field" showed that everything had been created correctly and was in the right place, two people were able to see it as intended, and two others had to physically add the field by going to the "Show field" option. While I can sort of understand needing to add that new field via the Show fields option, it does not explain why fields that were always shown previously are now having to be manually added by multiple (but not all) users.