According to Talwara Ji there are many misprints/spelling errors in todays modern Gutkey Sahibs/Saroops of both Sri Guru Granth Sahib Ji and Sri Dasam Granth. He specifically mentions how many of the foot letters are missing today. Such would be the case in Ardas where Rara is omitted from Har Krishan.
Another panthic scholar Giani Harbans Singh Ji has pointed the differences existing in the puratan saroops and the modern day saroops. In the verses from Ardas which you have mentioned the modern saroops writes the pangti as
ਸ੍ਰੀ ਹਰਿ ਕਿਸ਼ਨ ਧਿਆਈਐ ਜਿਸ ਡਿਠੇ
ਸਭਿ ਦੁਖਿ ਜਾਇ ॥
Puratan Saroops write the pangti as
ਸ੍ਰੀ ਹਰਿ ਕਿਸ਼ਨ ਧਿਆਈਐ ਜਿਸ ਡਿਠੇ
ਸਭ ਦੁਖ ਜਾਇ ॥
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥