First check the water lines at all four connections for signs of a leak. Now turn on the washing machine and allow it to go through at least one large drain load. Before pushing the machine back towards the wall, and forgetting it, check that water isn’t leaking anywhere. When you run a test load you can catch any problems before everything is back into position and out of sight. This can save you from a flood or maybe even a small leak that you may not catch right away.