Looking for $4M+ I/O Refinance Loan in CA: Where to Start?

[Chase Banta]

Disclaimer: I have a smart partner with bandwidth problems. I am the dumb partner with bandwidth, so I am out asking novice questions.

We purchased a 36 unit property in northern California using a combination of a $4M bridge loan at 7.75% I/O and $2M cash on 12/10/2021. We've recently had 3 broker's opinions of value come in at $8.5M. We've found a refinance loan of $4.975M at 3.4%, but we want to explore what I/O options may be available to us. So far we've been told by one lender that our market is too small, so they aren't interested.

Where would we go/what should we do to shop in volume for what we're looking for?