Pay stubs for rentals?

Hi there, my family and I are in the process of beginning tenancy in a rental flat in Scotland, but we have hit a road block. The agency uses a 3rd party to check references. I work remotely for a company based in the U.S., and when I moved to the UK about a year ago they switched my position from an employee to contractor, and in that process I stopped receiving paystubs and began receiving all payouts via PayPal.

I’m still doing the exact same job, working the exact same hours, I just receive my pay differently and no longer have official paystubs. My work provided a proof of employment and pay certificate and letterhead to the company, but now the reference checking company (Let Alliance) is saying they still can’t verify my income. Just curious if anyone knows anything else I can do? Can I reach out to the rental agency themselves, or will they require me to go through this 3rd party route? Is it up to the discretion of the landlord? We’ve worked so hard and come so far, so this loophole we’re in is really disheartening, especially after we’ve put down a 2000 pound deposit.

Thanks for any advice.