Lock Screen notifications from Messenger app on iPhone.

I have an iPhone 12 and since the last Messenger update I now get constant lock screen notifications. Before if a friend messaged me and I opened Messenger to talk, that first message was all that flashed on my screen. I almost always go to my laptop to chat with them, so my phone is idle, but every single time they answer me the message flashes on my phone screen & it never did that before when I moved to my laptop. How do I stop this without turning notifications off for Messenger?

[Re-Titled By Moderator]