When you use NTEXT or NCHARVAR(MAX) datatypes in Microsoft SQL Server 2017, the stored procedure (no SP:CacheInsert in trace) gets compiled but does not get cached for database compatibility level 140 or 150.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
This problem is fixed in the following cumulative update for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Learn about the terminology that Microsoft uses to describe software updates.