Rule fires incorrectly when BigDecimal equality is involved in a pattern after upgrading to 7.13.2

Issue

After upgrading from 7.11.0 to 7.13.2, JUnit test started to fail because rule fires incorrectly even though condition(s) does not match with the facts.
It seems to happen if there is equality condition for BigDecimal type property.

e.g.

    when
        $p1 : Person( name == "John" )
        $p2 : Person( name == "Paul", age == $p1.age, salary == $p1.salary )
    then
        ...

Note: salary is a BigDecimal type property.

For instance, if there are following 2 facts,

John : age = 30, salary = 10
Paul : age = 28, salary = 10

this rule should not match because ages are not the same, but this fires with version 7.13.2.