Student visa renewal

So my school passed my documents for student visa renewal, I was the only one who didn't receive the visa. The immigration asked for additional documents such as my kyuryo messai, bank statement and an essay regarding my baito working hours. I didn't do so much part-time not until April of this year since I got a part time at the airport where they required me to work 26 hours. I did change my part-time three times because the previous ones didn't suit me. From April to May, I was also doing Eikaiwa for one hour a week along with the part-time at the airport but I eventually stop teaching since I need to focus for JLPT. My sensei also don't know the reason for the delay of my visa but I'm kind of worried. Also, is it true that pero month you can only work until 112hours?

Work hours are counted per week (or per day during the school holidays), not per month.

Student visa holders cannot work more than 28 hours per week (112 hours per month)
It would be possible that immigration wants to confirm this.

If you really want to know the reason you should ask immigration, but I do think you know the reason.
Since they ask your bank statement and working hours etc which is all related to work.
It seems they want to confirm you are within the requirements of the visa.

Student visa holders cannot work more than 28 hours per week (112 hours per month)

One month is not the same thing as four weeks (except Febuary on non-leap years if 1 February is a Monday).

clearly stated 28 hours a week.
Forgot question mark between the ()

Thank you very much. It's almost two weeks since I passed the additional requirements. My classmates received their visa within 3 days after passing the requirements that's why I'm quite worried about it.