This seems to be happening in a non-English environment. I was in a Japanese environment.
Any slugs will remain empty in the newly created category and there seems to be no problem
For reference, you can go to the edit screen by accessing this as a temporary solution.
Change the value of the number in the category accordingly. https://example.com/c/5-category/edit/general
I’m not sure if this is just my problem or a common bug, but I hope it helps.
I was able to reproduce it in the above step.
Even with newly created categories, the category edit button causes a 404 error when using Unicode slugs.
Hmm, I’m not able to reproduce the 404 with the slug generation method site setting set to encoded. I believe this should be enabled by default when you use a relevant default locale option.
I didn’t like long slugs and had turned it off before.
Selecting’encode’ for the slug generation method resolved the 404 error.
In such a situation, I think that it could be prevented by not accepting multi-byte characters or if there was a cautionary note.
In any case, it’s strange that the encoded string was assigned to the category that was emptying the slug …