They mean different things. You will need to decide which matches your situation.
I have some questions on problems on the textbook.
This means regarding the textbook itself. A better way to say this might be:
I have some questions on problems regarding the textbook. I think it is too old and does not address current affairs.
I have some questions on problems from the textbook.
This refers to problems taken from the pages the textbook. Of course they are written on the pages in this example.
Finally you could also write:
I have some questions on problems in the textbook.
meaning problems written inside (on the pages of) the textbook. I think this would be the best option if you are referring to problems written in the textbook.