Interesting question! What does DSO at your Uni say? Don't think it fits in your I-983 anywhere. STEM OPT income goes on W4, not 1099. Now, non-residents can own property and make rental income on it, but that wouldn't be via 1099, would it!?! I'd poke the realtor that sold you the flat/condo as they're required to take some licensing certs that surely cover "taxes on rental income for non-residents" subject matter. A quick search on airbnb suggests your income goes on W-8, and your realtor would say the same. I'd research rather than "hope" when it comes to status violation. https://www.airbnb.com/help/article/510

It is not a violation for a property management company to ask for your SSN in order to host your home on Airbnb. Airbnb may require your SSN in order to send you a 1099 form, which is a tax form that reports your income from Airbnb. It is important to keep in mind that Airbnb is required by law to report your income to the IRS if you earn more than a certain amount in a year.