Dear Jonah,
Thank you for posting in Microsoft Community. We are happy to help you.
I understand that you have a concern on folders named with numbers and it is not in order when filtering A-Z. Apologies for the inconvenience caused to you by this behavior. I did the testing on my side and I can see the same behavior. Libraries will crawl the items by the first character and followed by the second. Since 1 and 10 starts at 1, 10 will be next to 1. If I will create a new folder 11, it will be next to 10.
I would suggest you to raise a ticket Get support - Microsoft 365 admin | Microsoft Docs to check this behavior with our Support Engineer.
We look forward to your response. Thanks for your kind understanding. Stay safe and healthy always.
Sincerely,
Zee | Microsoft Community Moderator
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