Do I need to tuck my shirt into my pants for a single-breasted suit on the wedding day? It will make the belly of the suit bulge a little. ..
This situation is normal. I suggest you change a compliant belt first. Try to tie it tight. The shirt bulges normally. If you feel uncomfortable, usually, you don't have to press that button. When you go on stage or when you really need to buckle. Rearrange your shirt before buttoning it. And try to keep it that way.