It happens that printer drive does not behave as expected. One thing you can try is using embedded "Generic / Text only" printer driver instead.
Important
This driver can be used with ESC/POS print type only.You can read more about ESC/POS printer type at "Setting up ESC POS printer" article.
Add printer driver
To add printer driver, go to Control Panel > Devices and Printers. From there, click "Add a printer" button on top.
Wait until list of printers is loaded, and click "Printer I want is not listed", as in the screenshot below.
In next screen, select "Add a local printer or network printer with manual settings" and click "Next".
Next step is selecting a correct COM port for your printer. Within "Use an existing port" drop down select a port where your printer is physically connected and click "Next".
In next screen, you will be presented with the list of available printer drivers. Find "Generic" on the left, and select "Generic / Text Only" (use the latest version, if available). Once you have this printer selected, click "Next"
In case you had this printer driver installed before on your PC, you may see the screen asking you to keep existing driver or replace it with the new one. Select recommended option and click "Next".
Type a printer name or leave it the default one (recommended) and click "Next"
Once your printer driver is installed, you will see a screen asking you to share new printer on local network. Based on your preferences, if you wish to share the printer or no, select correct option and continue by clicking "Next" button.
You have successfully added a printer. Click "Print a test page" to confirm it is working as expected and click "Finish" button to close the wizard.
Selecting new printer in Aronium
Once you have added "Generic / Text only" printer to your PC, you will see it in the list of available printers. Next step is to select this printer as your receipt printer in Aronium, as described in "Print options" article