plugin dumps code output at the top of every page with PHP 7.4.3

This plugin works fine with PHP 7.3.20, but when I upgrade to 7.4.3, the plugin dumps a great amount of code at the top of each page on my website and each page on the admin site. I can tell it comes from this plugin because the code has strings like “text” => __(‘English (EN)’, ‘bverse-convert’)); also, as soon as I remove this plugin (and make no other changes), the problem goes away. I’m on version 1.3.6 which should be the latest. This is on WordPress 5.4.2. Thanks in advance.