The first query does not include any @odata.count information, the second does.
https://graph.microsoft.com/v1.0/me/messages?$count=true&$select=id&$top=0
https://graph.microsoft.com/v1.0/me/messages?$count=true&$select=id&$top=1
Possibly related to https://github.com/microsoftgraph/microsoft-graph-docs/issues/10801
Originally asked in https://github.com/microsoftgraph/microsoft-graph-docs/issues/13710