With Instant Client you shouldn’t set ORACLE_HOME. I think you have set this to get your wallet files read? If you had put those files in the default location ‘/usr/lib/oracle/19.3/client64/lib/network/admin’ (note the extra ‘/lib/’) then you wouldn’t have needed to set the variable. The ‘network/admin’ directory is pre-created ready for use. (Internally for the libraries ‘/usr/lib/oracle/19.3/client64/lib’ is the ORACLE_HOME for this Instant Client install.)

With Instant Client 19.3+ RPMs you don’t need to set LD_LIBRARY_PATH, since ldconfig is run automatically when the RPM is installed.