Voucher in the checkout does not update directly

Hello, there is a problem with your plugin in the checkout. If I want to add a voucher there (no matter what kind of voucher) and I click on the apply button, nothing happens. Only after reloading the page the voucher is displayed at the bottom.
If I deactivate your plugin, the problem no longer occurs and everything works without any problems.
Strangely enough, if you enter an incorrect voucher, an error message appears immediately and even if I enter a voucher it is displayed correctly. It only doesn’t work properly when adding, but only in the checkout. It works in the shopping cart.

Can you please help me?