Well well.... just found out that 
@Mouth's and my problems are the 
same problem... 

For everyone who has the same problem that either the PowerTip is not on top on the z-index or not showing up at all... It is just a 
typo issue... for use with UIX YOU NEED to adjust the CSS template... (for the default theme it seems to be no issue)
    /* PowerTip Plugin */
#powerTip {
    cursor: default;
    box-shadow: 0px 12px 25px rgba(0,0,0, 0.5);
    background-color: #FFFFFF;
    border: 1px solid rgb(240, 240, 240);
    border-radius: 6px;
    color: rgb(44, 44, 44);
    display: none;
    padding: 10px;
    position: absolute;
    white-space: normal;
    
max-width: 400px;s
    z-index: 2147483647;
}
The "s" after the ";" prevents the z-index from being processed at all... just delete it and it works...