Additional chat-related features and issues within Microsoft Teams for business
Hi Andrii,
If the list is set to Custom, it's reasonable to expect chats to stay exactly where you place them. According to Microsoft's documentation, chats and channels should be manually reorderable when the list is sorted by Custom. If you're already using that mode and the behavior is still inconsistent, this may be an issue with the current Teams client rather than something you're doing incorrectly.
As a quick test, you could try creating a new custom section and checking whether chats can be reordered normally there. Additionally, clear the Teams client cache and restart Teams to see if the issue persists.
If the problem continues, the best next step would be to have your IT administrator open a support ticket with Microsoft via the Microsoft 365 admin center. A technical support engineer can then initiate a remote session, review backend settings, and run diagnostics. If needed, they can escalate the case to specialized engineering teams who are well-equipped to perform advanced troubleshooting and provide targeted solutions.
For guidance on how to request support in the admin center, share this link with your admin: Get support - Microsoft 365 admin.
If you are unsure who your IT administrator is, you can refer to this official Microsoft guide for assistance: How do I find my Microsoft 365 admin? - Microsoft Support.
Wishing you a quick resolution. Feel free to let me know if there are any updates.