I believe this is a bug. I noticed this behavior as well with input_text entity inside entities card. Using it outside popup it worked fine. But as a popup, it didn’t update the text when changing. Closing and opening popup showed the new state. So if sergio_pt’s suggestion doesn’t work, it’s a bug with either browser_mod or how Lovelace handles browser_mod popups. In that case you should create a ticket at browser_mod Github and hope it will be solved in the future.