You're likely overfilling the reservoir or not closing the lid correctly.
For pitchers with a "Max Fill" line, only fill cold water to that line. Do not overfill. Close the Fill Lid completely and firmly after filling. For the Lake pitcher model, fill until the Fill Lid closes automatically.
If that's not it, check the filter installation. The filter groove must line up with the ridge inside the reservoir. Press the filter down firmly to ensure a tight seal. A misaligned or loose filter can cause leaks.
Heads up: Only open the Fill Lid when you are actively adding water. Do not leave it open for more than 5-8 seconds, as this can activate the indicator incorrectly. Also, always wait until the reservoir is empty before refilling it.