Struggling to connect with family: The gap between formal Burmese and Yangon colloquialism

I'm a heritage learner, and I’ve been studying from a formal course, but when I try to speak with my grandparents, they laugh and say I sound like a news presenter from the 80s. I want to sound natural and warm, but I don't know how to transition from the formal curriculum to the register actually used in my family home in Myanmar. Does anyone have experience with resources that focus on regional informal speech rather than the standard state-approved language?