ORA-01109 Error (Database Not Open), But It's Open in SQL Plus - Oracle SQL Developer

I'm getting the error "ORA-01109: database not open" in Oracle SQL Developer, in Oracle Database 19c and SQL Developer 21.2.1 Windows 64-bit. I've gone into SQL Plus to open the database and used commands like "ALTER DATABASE OPEN;" and shut down/restart the instance to open the database. It was originally on Status "MOUNTED," but it now says Status is "OPEN" when entering the command "select instance_name, status from v$instance;" (instance_name is listed as "orcl"). However, I still get the same ORA-01109 error when opening my database, "CS4347" in Oracle SQL Developer. How can I open this database in Oracle SQL developer? This error occurs when I try to expand the database or connect to it.