While charging the galaxy s10 pop-up window about unplug charger

[Q : While charging the Galaxy S10, pop-up window about “Unplug charger” suddenly appear and charging is sometimes stopped even when device is not charged fully. Why is this?]
A : During wireless or wired charging, the device and the charger may become hot. 
If the device heats up or the ambient air temperature rises, the charging speed may decrease automatically.
When the device heats up or becomes to specific temperature during charging, charging algorithm to protect device overheating operates and accordingly the charger may stop charging with message pop-up about “Unplug charger” and the features and performance may be limited. This is a normal operating condition to prevent damage to the device. At that time, wait for the device to cool down and then begin charging the device again.

If overheating persists, please contact to Authorized Samsung Service Center with your device.