Pull the bowl and check the connection at the floor.
When installing a bowl, it's important to put the wax on the floor flange, not the bowl.
If the flange is below the finished floor, it will need either a thick wax, or two rings.
Often I've seen wax stuck to a bowl drop off the bowl and land across the drain opening.
I have also seen users put too much down to test it. Sometimes that has involved crumpling up the wax paper from the wax and trying to flush that down. That is never a good idea.
Check to make sure that the fill tube from the fill valve is pointed into the overflow tube.
This refills the bowl after a flush. Unless the bowl is at the correct height, there won't be enough power to the flush.
The bowl rates at 800 grams, which is well above the 500 gram ratings that I refer to as super. The EPA Watersense approves at 350 grams.