Switched from Samsung messages, my most recent conversations are not showing?

I downloaded Google messages because of the forced switch coming up. I'm literally in the middle of two separate text conversations and when I open Google messages, neither of them is there? They're both RCS and I do have the RCS feature turned on. I can go back and make samsung messages my default again and when I do, I do indeed see those two people have continued to text me in the meantime. They just don't show up in Google messages. So.. is this going to be an ongoing problem? Does Google messages take a long time to update RCS messages when I'm not connected to a wifi? Should I start looking for alternative apps for when this change actually gets forced?