ORA-04020: deadlock detected while trying to lock object - Oracle Package
Look at this webpage https://docs.oracle.com/cloud/latest/db112/LNPLS/nameresolution.htm#LNPLS017, especially the INNER CAPTURE section. 
Does the package exist on both sides of the link or only one? 
What does the ORA-60 deadlock trace file show?
What does DBMS_UTILITY.NAME_RESOLVE show for "SCHEMA2.PKG_NAMEHERE@SCHEMA2.LINKNAME.INT@SCHEMA1"?
Do the DBLINKS loopback?