We always liked this toilet for it's strong and quick flush (American Standard Chamption, I believe, with a 4" flush valve), but now we consider it a problem especially seeing the water 'burping' up before going down, and it causes a similar burp and sucking of some water from the the adjacent bathroom...
Short video clips...
We just remodeled the bathroom adjacent to this one and the new toilet (wall-mounted) gurgles a bit and has some water sucked out when the American Standard is flushed. The bathrooms are adjacent but the toilets are on different walls and not directly back-to-back. The American Standard is in an updated bathroom done before we bought the house.
This behavior was happening before the new bathroom remodel as well but it wasn't pronounced or particularly problematic; now the gurgling in the new bathroom is louder and the wall-mount toilet bowl has less water to begin with, so we definitely want this addressed.
Yesterday the plumber snaked all the vent pipes in the house and found a bit of leaves but nothing that made any difference.
The new toilet and one other in the house work fine and do not affect each other when flushed
I realize this is a trial-and-error type of problem and I would like to get it resolved in the smartest and least costly way (hence my posting here...) Appreciate any advice.