Until recently there seems to be something going wrong with the Character's info boxes. They seem to not want to appear and finds a problem with "parsing" the info box. I'm not sure how to handle this situation if we need to start back from scratch or by contacting Fandom.
Here is an example:https://banana-fish.fandom.com/wiki/Ash_Lynx
This one, to fix the problem as it was previously we could see the There is a problem with parsing the infobox message then scrolling down at line 77 the issue was shown. Checking the history shows which edit made the message appear, which was when data was removed which causes the content to disappear since the code is looking for the <data> and </data> values but one was absent. Kind of like how both reference tags are needed <ref> </ref> otherwise the code decides to just hide everything. All sorted now!