Microsoft Graph To Do API doesn't fetch everything

Question

Hello,

I am encountering a synchronization issue with the Microsoft Graph To Do API. This problem affects the syncing of Microsoft 365 (Hotmail) task lists across multiple platforms, including Mac and iOS, when using the API endpoint:

GET https://graph.microsoft.com/v1.0/me/todo/lists

Some task lists fail to sync, and this problem is not isolated to third-party applications but affects any application that utilizes this endpoint. Initially, it appeared to be a limitation on the number of lists that could be synced, so I reduced the number of my lists. However, the problem persists with certain lists still not appearing. Additionally, I've experimented with altering list groups, themes, and even removing emojis from list names to eliminate possible formatting errors, yet the inconsistency persists.

Further investigations using the Graph API explorer confirmed that the issue originates from the API itself, as the missing lists issue could be replicated directly. Interestingly, the following methods allowed for the retrieval of all lists:

Employing the delta query feature:

GET https://graph.microsoft.com/v1.0/me/todo/lists/delta

Applying a filter directly in the API request:

GET https://graph.microsoft.com/v1.0/me/todo/lists?$filter=displayName eq 'Shopping'

Reports from other users reflect similar experiences:

• Microsoft Graph To Do API doesn't return all task lists
• Microsoft Graph To Do API only returns 10 tasks

Given that the issue lies with Microsoft's Graph API, could there be an unrecognized bug or a limitation not documented? Any insights or solutions to achieve consistent synchronization without these workarounds would be greatly appreciated.

Thank you!