Personas, co-creation, and agile [on hold]

Good afternoon folk

We are a UX team, working agile to design, test, build healthcare products.

I wanted to hear from designers, researchers, product managers, anyone working in an agile team, with an opinion to share.

In past projects we've performed user research (interviews, journey mapping etc) and created personas.

This helps with a shared understanding who we are designing for, and why. We put the users at the center of conversations. But, as the project evolves and development/design is in full flight, personas are used less and less.

How do you keep personas at the heart of agile product development?

Thanks