Is anybody else having an issue when they right click on an SP, and not seeing the option to execute the SP? Only option that I have is to script as execute. I am running SQL Server 2016 express.
Too long for comment!
I suggest that you back up the database now. Full and transaction.
Then check the Compatibility level. Change it back to your previous version of SQL server. Take another back up (to a new file!!).
Now did you upgrade the whole of SQL server or just SSMS? You could just install another earlier version of SSMS and leave the existing server in place and running, test to see if the functionality is all still there with the new (older) SSMS and the old (Ok most recently installed SQL Server).
Microsoft are doing monthly releases of SSMS so it is changing fast - which can mean bugs, but the server should be more stable, so the problem could just be a SSMS issue and your database could be fine.