Commercial building, toilet waste coming through floor drain

[bchydrosucks]

Folks: I do maintenance on a couple commercial buildings. One is a 4 story building, 6 months old. One bathroom on the 4th floor is approximately 20 feet by 14 feet. It has two toilets in the corners and on the other wall 2 urinals and 2 sinks. What has happened is one toilet has started to malfunction by not flushing and draining when used. Instead of this toilet overflowing, there is a drain in the middle of the floor; and the crap and water comes up through the drain. This is causing a large area (25 sq. ft.) of this human waste. It has been scoped by a plumbing professional with no construction debris.
Because this is the 3rd time it has happened, I have my concerns.
Does anyone have an idea on what may be causing this?

 

[Mr_David]

You had a professional come and scope it with a camera?
Can you get access below?
Acoustic tile ceiling are common in commercial building and maybe you can see how the pipes are configured?

 

[stevemachine]

I would hazard to guess there are some issues with grade but like mr david said drop some tiles otherwise you have to cut into the drywall. Something has to be done and no other way but to see it first hand

 

[ExtraMilePlumbing]

Where was it scoped from ?