When using the Platform Manager or Power ManagerII devices; POWR1220AT8 POWR1014A and POWR6AT6, it is important to know the loading and driving source of the full set-up.
In a case where there are just a few I2C loads the designer needs to consider the capacitance that each of these hangs on the open drain signals SDA and SCL.
As a general rule when using 6-8 devices or more, buffering may be needed. In the cases where there are just a few devices use 2.2k to 4.7k pull-ups to achieve a good rise-time and signals for each device.
A quick scope check will assure you have good signals, but be aware of the capacitance of the probe acts as a load too.