Primary Keys On TVPs And Plan Forcing

Michael J. Swart notes that you cannot force query plans if you’re using a user-defined table type with a non-named primary key constraint:

When defining table variables, avoid primary key or unique key constraints. Opt instead for named indexes if you’re using SQL Server 2014 or later. Otherwise, be aware that plan forcing is limited to queries that don’t use these table variables.

Helpful advice when dealing with user-defiened table types.  Read the whole thing.