SQL Navigator 7.5 crashes when connecting to a 19c DB

I have SQL Navigator for Oracle (Ver 7.5) (64b) with an Oracle client 19 (64B) on my laptop. I am able to connect to some Oracle Db 19c . However when connecting to certain 19C DB's, the SQL Navigator crashes. I am able to connect to the same Database ( where I was having issues with SQL Navigator) using Oracle provided "SQL Developer" and using the same TNSFILE that was used by SQL Navigator.
Any suggestions on what might be causing this issue.