Created attachment 39610 [details]
Reproducer with conditional formatting rules

With Excel, the conditional formatting the rule "compare cell between 2 values" will evaluate the formula both ways:
 - val1 < cell.value < val2
 - val2 < cell.value < val1

There is no assumption what is the lowest value and the highest one. 

With Apache POI, the evaluation is done one way which suppose that the lowest value is the first one and the highest one is the second:
 - return cellValue.compareTo(v1) >= 0 && cellValue.compareTo(v2) <= 0;

https://github.com/apache/poi/blob/ae2f0945cd2ab37260e46ab46c54b8f68a131aea/poi/src/main/java/org/apache/poi/ss/formula/OperatorEnum.java#L92

As a consequence, each time the lowest value is passed as a second value, the expression is always false.

Code should look like:
 return (cellValue.compareTo(v1) >= 0 && cellValue.compareTo(v2) <= 0 ) ||
                 ((cellValue.compareTo(v1) <= 0 && cellValue.compareTo(v2) >= 0 )) ;