Toilet issue

Toilet will flush completely, but in process of flushing there is a very large bubble that occurs and splashes on the seat. We have snaked the toilet, we have cleaned the stack, we have replaced the tank guts. Also note, thus toilet is about 9 yrs old, the master bath is right behind it and uses same stack. No issue with any other toilets or sinks. Any ideas?

I can't be specific, but bubbles are caused by the discharge hitting an obstruction and bouncing back sending a bubble of air ahead of it. Have you had any work done lately? Has the toilet been pulled and augered from the hole? If not you might try that. Good luck Tom