Graph /users query with mailboxSettings filters/expands excludes unlicensed users

Hello Microsoft Graph team,

I would like to report what appears to be a bug in Microsoft Graph user queries involving mailboxSettings.

Issue summary:

When mailboxSettings is used in a filter or expand clause on /users, unlicensed users are not returned, even when they should match the filter.

Example scenario:
Filter used: mailboxSettings/userPurpose ne 'room'

Observed behavior:
Users without Exchange license/mailbox are excluded from results (or result set appears truncated to mailbox-enabled users).

Expected behavior:
All users should be considered in /users query evaluation.
If a user has no mailbox settings, behavior should be consistent and documented (for example null handling), but those users should not be silently dropped from /users results unless explicitly filtered out by query semantics.

Reproduction steps:

1. In a tenant with mixed users:

• Licensed mailbox users
• Unlicensed users without mailbox

1. Run a /users query that includes mailboxSettings in filter and/or expand.
2. Compare returned users with a baseline /users query without mailboxSettings conditions.
3. Notice unlicensed users disappear when mailboxSettings is involved.

Sample request patterns:

• GET https://graph.microsoft.com/v1.0/users?$filter=mailboxSettings/userPurpose ne 'room'
• GET https://graph.microsoft.com/v1.0/users?$expand=mailboxSettings&$filter=mailboxSettings/userPurpose ne 'room'