Water flowing back to Washing Machine

[bwspot]

I do live in the condo that uses one drainage pipe for sink, dish washer and washing machine.
Many times i see water in washing machine.
The drain pipe from washer goes up and has a loop already.
If i open the cleaning opening and pour some water i can see water immediately draining via the cleaning port instead of going back to main drainage pipe.
Should the drainage pipes be at angle to force the water go into the main drainage pipe direction?
I had my drainage pipe cleaned few times by plumbers via the Shnaking/Cabling method but the issues comes back and even happens just after the pipe was cleaned.
What is strange that i can forcefully pour out tons of water into the sink to test and nothing comes back the washing machine.
Then during cooking prep and cleaning dishes in the sink (NOT washing machine which i barely use) water will many times end up in the washing machine.
Cannot find exact pattern when it happens.
I wonder if the pump in the washing machine has some sort of valve to block the water coming back or its just the pump and when water comes back it will get back to the washing machine?
Edit: CHECK VALVE

I found that the pump is this one but i dont know if it has check valve
https://www.searspartsdirect.com/product/2ik0lrn6s3-0026-417/id-132611913

I have this idea to either:
1. Install manual stop drain valve and open it only when i use the washing machine
2. Install some sort of drain flow control that only allows flow into one direction?


Any advice from the pros what would be the best solution?
Attached some photos of how the pipes are connected.

 

[GReynolds929]

Where are you located because nothing about that setup is correct for US plumbing.

 

[bwspot]

Where are you located because nothing about that setup is correct for US plumbing.

Chicago.
Those are old condos where they set it up like this.

 

[GReynolds929]

Ok well, seems to me that if water is backing up into the washing machine that the drain is obstructed and needs cleared. The drain pipes could be back graded away from the drain causing issues. I would think that if it’s backing up into the washing machine you would see slow draining or standing water in the sink. Do you fill the sink when doing dishes and let it all out at once when you’re done? You can put in a check valve, or ball valve if you want. It would be a temporary fix at best and definitely not to code, although neither is the current setup. I would recommend a proper fix if possible.

 

[bwspot]

Ok well, seems to me that if water is backing up into the washing machine that the drain is obstructed and needs cleared. The drain pipes could be back graded away from the drain causing issues. I would think that if it’s backing up into the washing machine you would see slow draining or standing water in the sink. Do you fill the sink when doing dishes and let it all out at once when you’re done? You can put in a check valve, or ball valve if you want. It would be a temporary fix at best and definitely not to code, although neither is the current setup. I would recommend a proper fix if possible.

When i pour lots of water i see water draining pretty well.
I dont see any water coming back when looking at the other side of the sink.
I assume if pipes would be clogged i should see water flowing back via other sink side.
I don't fill sink when washing dishes. I always was one by one quickly.
Sometimes when machine is draining water i will see i water go up in sink a little, but never above the bottom sink level.
Maybe the pump is too fast for the water to drain?

What i wonder if my washing machine has a check valve and if it broke and sometimes works sometimes does not?
Also, i wonder if those pipes are just too old and even cleaning them is not enough to completely make the the most efficient.

What does not make sense to me that if i try to. forcefully overflow sink i cannot get the water overflow in washer.
It mostly happens during my cooking, washing cycles.

Any check valve you would recommend for this scenario?