I'm a lead engineer for a highly technical product, aspects of which cross multiple technical disciplines. From working with him, the PM doesn't know even the very basics about computers but he's constantly trying to "help" with my work. For example, trying to reimage PCs or repair a motherboard. Why would he even try to help with something like this? He's tried (unsolicited), he can't. Not only is he just in my way (sometimes literally breaking things), he is also wasting his own time.
How do I know this? Because part of his job is showing the product to customers and I am constantly getting feedback from him that "he didn't know" that these key features existed, despite being part of the product for a year now. He is in the meetings with software devs and the rest of the product team. He has access to our product to try it himself, not to mention all the documentation being emailed to him as it is made. But it doesn't seem like he ever does anything with it. So he's constantly calling me for help on things that he should know by now. And frankly, it is taking up too much of my time.
Who should I talk to about this? Technically, he has more seniority over me in the product, obviously. But he is interfering not only with my work, but in a way that distracts from his own. Should I talk to my manager? Report it to his manager? Try to talk to him about it? I've tried to give him hints and tell him no (I manage to evade things I know he can permanently break), but he's persistent. Actionable advice would be helpful.