Problem lies in my iPhone 12 Mini, not my wireless charger. Almost all later iPhones come with a new feature called Optimized Battery Charging. This feature prevented charging to take place when battery power hit 80%. And when this feature enabled, it prevented charging to take place when the iPhone is hot in temperature. During when I charged my iPhone, my phone turned hot quickly partly reason was due to the trapped heat from the phone protection case. When my iPhone turn hot, the charging are no longer working no matter how many times I recharge it again. Due to this, I was unable to charge my iPhone until it cools down. The time taken for it to cool down can be long, causing the charging process taking up a long period of time. But if I were to turn off the battery optimizer, it may damage the battery and reduce the battery lifespan. Hence, I tried with a way to put my iPhone into freezer, took out after 1 minute time and retry the battery charge again. It works! Base on this experience, I found that the battery optimizer configuration from later iPhone are likely to stir up a lot of problems if it is not properly used. I would like to suggest all late iPhone user to be clear of how the battery optimizer works so that it will not cause up unnecessary problem. User's recommendation: When iPhone charging does not work, cool down your iPhone with freezer if possible. Do not turn off the Optimized Battery Charging, unless urgent charging is needed during rushing hours without freezer around. Remove iPhone protection case is also one of a way to fasten the cool down process.