Oracle 18c

Connecting to PDB as 'sys', I cannot figure out how to connect to a schema other than 'sys'.

Here is what I have tried after logging into Oracle 18c CDB as 'sys':

ALTER SESSION SET CONTAINER= PDB;
conn myschema/mypasswd

--and also tried right from CDB

conn myschema/mypasswd@PDB;

Both approaches fail to get me connected as 'myschema' within the PDB.
Any suggestions?