We had a water hammer issue steming from our washing machine (LG) . When the washer started to load water , the pipes would shake upstairs

My plumber suggested that I install two mini arrestors on the washer inlet hoses.

I disconnected the inlet hoses from the washer and ran the hoses into arrestors that connected the arrestors to the washer

The connection seemed fine after the first wash I noticed no leaks from the connections

However after a few wash loads I did notice some water on the tile floor. Since it was a small amount and nightime I figured i would address the issue in the morning

In the morning there was a sizeable amount of water on the floor despite the washer not being on ( the water connect on the wall was open)

The water contined to flow thru the hoses and onto to the floor

I noticed there a small drip of water coming from the top back of the washer, just below the hose connection. This happened if the washer was on or off

I disconnected thje arrestors, dried the floor and did more laundry. There was no water on the floor since i disconnected the arrestors.

What did I do wrong, and what caused the water on the floor

Some evidence point that this was an arrestor issue, but I am not sure why