Last name only to address a teacher by their first name is disrespectful.
I agree with you with the respect of last name Brianna.
Whether it is appropriate to use a teacher’s first name depends entirely on cultural norms, your education level, and the specific school’s policy. Generally, using a title and last name (e.g., Mr. Smith or Mrs. Davis) is the safest and most respectful standard for younger students.
Very explained about respect for last name for a teacher, especially students Adeoye!

Right Olalekan, last name is appropriate to call a teacher.
Thanks for sharing! ⭐️