Hi Victor,
I’ve edited wp-config.php to enable WP_DEBUG and WP_DEBUG_LOG and tried to buy a ticket several times, to feed the debug log. I’ve attached the log file to this message (I had to add .png suffix as .log file was not accepted).
I am not sure where to look for console errors, to be honest, but here is a link to an event with tickets so that you can check yourself:
https://www.bezec.eu/event/spolecny-vybeh-ve-stromovce/