Sounds like a combination of your DTI and future LTV affecting things now. It’s really not much more different than saying you’re selling house #1 to buy house #2, and managing that contingency.
Your challenge will be to find a renter that’s willing to meet your terms and timing, while being able to provide all the cash upfront. If you’re going to be a first time landlord in CA, I’d look up the pros and cons before heading down that path. CA is more renter-friendly than landlord-friendly.
You can also make your purchase contingent on renting your current home, but it will be hard to find a seller willing to accept those terms. It is a buyers market so it might not be that hard.
Check out American Federal Mortgage out of NJ. The guy I know doesn’t do MD but others in the company might. Best rates I’ve seen and a few family members have used them.
Lenders are all over the place. People move from company to company. One buys another out. It’s a massively churning market with little stability. Brokers are good at shopping around but take a cut. There are huge differences in underwriting speed and competence. Once you sign, your loan may be sold off quickly. Rates shift constantly. It’s the wild west.