Why group of google home speakers sometime one speaker only works?

Hello everyone I am new here, and this is my first topic.
I have to google nest mini (2nd Gen) and they are both connected to the google home app and I made a group of the two speakers. after I installed home assistant and started it I integrated google cast integration and discovered the two speakers along with the third one which is the group and added them to Lovelace.
The problem is after some time when I turn on the group from Lovelace it will turn on only one speaker, I thought it was only a glitch I tried to play something and its only plays on one speaker and I checked google home app they are both in the group. So I deleted the group and created another one same problem exactly it work only for one day.