When using jqxNumberInput and allowNull I expect the display to start empty instead of zero. I saw one solution about setting the initial display to empty but this does not help if the user wants to delete the value so it is empty again.
Surely allowNull should mean that the value can be empty and that the user should be able to just press delete to show a value has not been entered.
You could add custom logic to achieve it.
Because the default behavior is to show zero when the current value is deleted.
Please, take a look at this example it could be useful.
I hope it will help but please, let me know if you have any questions.