Toilet bubbles and gurgles after capping vent stack
The bubbling and gurgling sounds from the toilet(s) is an indication of poor venting or a plugging issue. Also, you should not have to "flush it a couples off times for things to go down" unless there is a special circumstance (like too much paper... or something).

Call a reputable licensed plumber and have your entire system assessed, including camera inspection. Then pay appropriately to have the root cause addressed.