Why is IP68 waterproofing of the POCO X7 Pro not effective?

Sorry for the inconvenience caused to you. This phone supports dustproof level 6 and waterproof level 8.
The supported IP68 water resistance conditions are as follows:
1. No flowing water, water depth of 2 meters;
2. Test time 30 minutes;
3. The temperature difference between water and product is no more than 5 degrees Celsius.
IP68 protection capability will gradually decrease due to wear, bumps, high temperature and humidity, acidic and alkaline liquid environment, etc. during use. It is not permanent. It is recommended that you use it under reasonable conditions. The harsh application environment will cause the dust and water resistance of the phone to decrease rapidly. Do not charge the phone in a wet state; damage caused by immersion in liquid is not covered by the warranty.