Erin Stellato has a roundup of Query Store bugfixes as of January 2019:
The latest CUs for SQL Server 2016 and 2017 contain some important Query Store fixes that I thought worth mentioning for those of you on either version or those of you looking to upgrade. As of this writing, the current CU for SQL Server 2016 SP2 is CU5, and for SQL Server 2017 it is CU13. Many times we see fixes that make it into a SQL Server 2017 CU ported back to a SQL Server 2016 build. Interestingly enough, there are some Query Store fixes in 2016 CUs that are not in 2017 CUs. I don’t know if that’s because the issues do not exist in 2017, or if it’s just that they have been fixed yet in 2017. I’m planning to update this post if the fixes are added down the read. So here we go, in descending CU order…
This post is a great reason to keep those SQL Server instances up to date.