Is one excused for being ignorant of the ruling regarding leaving the hair unshaved after their first 'Umrah, believing it was not a condition, then completing a second 'Umrah for their mother with a shaved head after being advised, while remaining ignorant of the ruling on shaving when traveling?

Shaving or shortening the hair is a ritual in Hajj and Umrah. The state of tahallul (exiting the state of ihram) in Umrah is not complete without them. Therefore, if a person exits ihram before shaving or shortening, it is not considered valid, and similarly, his ihram for a second Umrah would not be valid, because he is still in his first state of ihram. His Umrah would be completed by exiting ihram through shaving, and there is nothing upon him if he was ignorant (of the rule).

Sheikh Al-Uthaymeen said: "Whoever forgets to shorten his hair in Umrah until he exits ihram and commits one of the prohibitions of ihram, there is nothing upon him because he is forgetful and ignorant. When he remembers, he must put on the ihram garments to shorten his hair while he is in the state of ihram."