Recently tried renaming my clan as I outgrew the old name Elder Masons. I attempted to change it to something related to the Dune franchise and it said the changes went through but instead my clan is just numbers now. I am unable to revert it back or change it to anything else. For clearance, I am the founder of my clan since i saw old posts saying thats the issue.
If it changed to numbers immediately, then something you attempted to put in would have been caught by the filter. Unless it was bad enough that the system actually banned your clan and you can no longer change the name, you should still be able to change it, but you'll need to choose something else. The issue could be because of the name, the tag, the description, or the motto you tried to use.