In your infinitescroll.php file you set the tab attribute - section that shall contain the module in PrestaShop’s back office modules list:
$this->tab = 'front_office_features';
but your module appears in Other category.
I also build my custom module (a payment module) and I want it to appear in Payment category but despite my settings $this->tab = 'payments_gateways'; the module is listed also in Other category. In fact it doesn't matter what you put on tab attribute, the module is always listed in Other category. Why?