It’ll be a pain, and your phones will not cease to ring but get a quote from

1.) Quicken/Large Bank
2.) Credit Union
3.) non bank lender.

In that order. Let them know you’re shopping a bit. Give them opportunities, to price match. It’s worth it. A lot of these guys have authorization to go pretty deep before you have to buy your rate down.

“Market has changed and the other guy I’m working with could offer me a better rate. Can you?”

Depending on where you are, I might contact Melodyets or Mulletino for #3.