I don't know if this is related to v2.19 of if this was a bug before.
bizarroAruthmetic is used in CollegeOfIdaho/setAlgebra_06_02_AddSubRationalExpressions/62IntAlg_17_AddSubRatExp.pg
as
Context()->operators->set(
'/' => {class => 'bizarro::BOP::divide', isCommand => 1},
'/ ' => {class => 'bizarro::BOP::divide', isCommand => 1},
' /' => {class => 'bizarro::BOP::divide', isCommand => 1},
'//' => {class => 'bizarro::BOP::divide', isCommand => 1},
'*' => {class => 'bizarro::BOP::multiply', isCommand => 1},
'* ' => {class => 'bizarro::BOP::multiply', isCommand => 1},
' *' => {class => 'bizarro::BOP::multiply', isCommand => 1},
'+' => {class => 'bizarro::BOP::add', isCommand => 1},
'+ ' => {class => 'bizarro::BOP::add', isCommand => 1},
' +' => {class => 'bizarro::BOP::add', isCommand => 1},);
As a consequence, the answer
$answer = Formula("($a + $b*$c x)/($b x^2)")->reduce;
does not accept the plus sign unless the space after + is removed in the above line, and even in the solution it shows up as $a $b*$c x instead of $a + $b*$c.