An INTERVAL datatype with a value ≥ 1 day and < 1 day+1 hour incorrectly displays as 24 hours in the grid:
select
level
, numtodsinterval(level,'day') i1
, numtodsinterval(level,'day') + interval '59:59.999999' minute to second i2
, numtodsinterval(level,'day') + interval '1' hour i3
from dual
connect by level <= 3;

Running as script correctly displays 1 day:
LEVEL I1 I2 I3
---------- ------------------- ------------------- -------------------
1 +01 00:00:00.000000 +01 00:59:59.999999 +01 01:00:00.000000
2 +02 00:00:00.000000 +02 00:59:59.999999 +02 01:00:00.000000
3 +03 00:00:00.000000 +03 00:59:59.999999 +03 01:00:00.000000
(Extension version 26.1.0.)