Plugin seems to wipe checkout information on entering details on checkout page

Hi, I’m using the free version of this plugin at the moment and I only have the bare minimum features enabled, I have it set to prevent reaching the checkout page if the subtotal is below 11.
Unfortunately, with this plugin enabled, the checkout page seems to resize itself as details are entered into the form which wipes all the entered information. I can’t figure out why this might be, it only occurs with this plugin activated. Notably, it even occurs if the plugin’s “Disable plugin” checkbox is ticked, I have to deactivate it altogether.
I’m not even sure how to go about debugging something like this, do you have any idea why this might be happening?