island loop

Plumber installed an island loop with this setup. He says it was done this way because connecting the vent back to the drain would cause more damage to the slab (this is a reno and we had to cut about a foot deep into the slab to make this happen). What problems am I looking at down the road?

I had an island loop installed with my kitchen reno. I opened the vent side cleanout and water poured out. Then there was standing water up to level of the cleanout. So the vent side of the loop isn’t draining. The drain side is draining though. This shouldn’t be possible if the loop was done...

Hi, New member here. I'm doing a kitchen remodel and removing a wall that housed a vent for the sink, dw, disposal...and need to create an Island Loop. There's an adjacent vent nearby that is also used for a washing machine standpipe. My question is, will the plumbing be to code if made per the...