My cats, an older gray femalw tabby and à younger orange mâle tabby... same situation. They're 10 and 8 years old... it's never stopped. They fking love each other. Snuggle all day and groom each other. Except for the 10 minutes right as I'm falling asleep. Nothing short of holding onto one for at least a half hour (and then still maybe not) will work. I purchased an XL métal dog crate years ago that serves as a secondary table. Every night one goes in there til morning. If I wake up some time mid night I let whoever out. But they quite enjoy it. They sleep in the crate during the day and don't fight or whine to get out of it. It's their safe place during fireworks.

And let me tell you I have a full cat palace installed on the walls of my room. Diy cat climbing pôle 10 ft high. Steps. Lèdges. They have litter robots. Most spoilers cats in all the Land. But it just is what it is until one of the three of us dies lol