WhatsApp makes screen "freeze" Samsung A35

When I open WhatsApp, the screen freezes a lot. Like I'm typing and it doesn't show until later, like 10 seconds. I changed the keyboard to gboard, it's a bit better but still. I get that notification "..not optimised for your phone. Screen touchedls may be delayed or not reflected"

I got this phone just a month ago. Why????!! Need solution to this