Rental Agencies - Short vs Long term

Hi all, I'm looking for a studio apartment but I'm having trouble finding a rental agency willing to work with me. I'm open to either short or long term, but all of the agencies I've spoken to say that I need proof of a short term stay and that they don't have long term available. I don't have proof of a short term stay since I work in a permanent job here.

Has anyone encountered the same? Is there a way for a resident to obtain proof of this, or should I look for long term agencies? All of the ones I spoke to say they don't have long term rentals available - if anyone has a recommendation of an agency with long term that would also be appreciated! I know coliving tends to be more flexible, but most of them don't have studios or the studios they have are super pricey