What did you do with the watch water wise. If you showered with it then that could be your problem. IP68 is not meant for the shower. Water resistance raitings are used to measure the pressure of water not the actual depth. You have the pressure of 1.5 meters for half an hour. The shower head puts out 40psi (normally), which is the equivalent of 30 meters of water or 3 ATM of water. If it does fall in water or you fall in water, if you move at all in the water then you put more pressure on it and it can break the seal. IP68 is also only meant for fresh water that is not moving. Steam from the shower has also known to get into phones in very rare cases.