TOAD 10.6.0.42 not processing substition variables in all cases

Just a little glitch… I have the code below in an editor window. If I ‘execute
as a script’, the substitution variable prompts once and works correctly for all
3 statements. If however, I highlight the selects individually and ‘execute’,
the prompt window appears, but the substitution only occurs if I’m running the
first statement…if I have either of the subsequent statements selected, the
substitution doesn’t occur.

SELECT *
FROM GENERAL.GUBOBJS G
Where
GUBOBJS_NAME = ‘&&objname’;

SELECT
ROWID, G.GURUOBJ_OBJECT, G.GURUOBJ_ROLE, G.GURUOBJ_USERID,
G.GURUOBJ_ACTIVITY_DATE
FROM BANSECR.GURUOBJ G
Where
GURUOBJ_OBJECT = '&&objname';

SELECT
ROWID, G.GURAOBJ_OBJECT, G.GURAOBJ_DEFAULT_ROLE, G.GURAOBJ_CURRENT_VERSION,
G.GURAOBJ_SYSI_CODE, G.GURAOBJ_ACTIVITY_DATE, G.GURAOBJ_CHECKSUM
FROM BANSECR.GURAOBJ G
Where
GURAOBJ_OBJECT = '&&objname';