I use floor non slip tape on a Vespa floor boards , which basicly sand type paper with a strong sticky back.
Wrap a bit round the end of you carb manifold, cut to fit. And it gives the rubber something to grip to.
I don't usually get give any useful advice, I'm the one who asks for it. But if your carb rubber isn't ribbed, this does work and also let's you position the rubber at a slight angle for those pesky carbs that foul on the Cowell or floor boards.
An adult may say this is a load of sh1te, but it works for me
As you were.
