Can I do freelance work on a student visa in Japan? (No reply from immigration)

Hey guys,

I’m currently a student at a senmon gakkou (vocational school) in Japan, studying software.

I already contacted immigration but haven’t received any reply yet, so I wanted to ask here.

I have permission to work part-time (資格外活動許可), but I’m not sure if freelance work (like web development, small online projects) is allowed under this.

I’m mainly thinking of doing freelance work to build my portfolio as a software student, not full-time work.

Has anyone here done freelance work on a student visa?
Is it actually allowed, and are there any important rules I should be aware of?

Thanks a lot!