My washing machine leaks water during the drain ...

Most probably it's a clog in the drainage (where the pipe is flowing water to). If this did not happen in the past, it's unlikely that the machine is flowing more water per-cycle.

Liquid drain cleaner is only good for clearing organic material (food, etc.) you have to get a snake which is a tool used by plumbers. It is a long strip of metal that you push into the drain pipe to free the blockage. If that doesn't work, call a plumber.

i am curious to know if you have found the answer to your dilemma.  i am a general contractor and my washing has begun doing the exact same thing.  i tried a 25'snake right into the drain behind the machine, i tried one of those expanding balloon things that create a seal and force high pressure water through the system, and just tonight i went to the roof and did the snake again and then i shoved nearly my entire garden hose into the vent with the balloon again.  my snake has come back clean each time i have tried it, the water does not back up at all or come out other drains when i leave it on full blast for a few minutes, and nothing else in the house is draining slow or having problems.  tomorrow my last resource is to get under the house and make a visual inspection.  i am curious if you did find a solution. i did a little reading and found that different machines will partially drain while they are filling up, others won't.  i don't know if mine is supposed to drain partially and might be missing that cycle so when it does drain at the end, the amount of water is greater than before.  does this sound remotely feasible to anyone?thank you.