Did Plugin or WordPress update break CF7?

When I updated to WordPress 4.8.1 and updated to version 4.8.1 of CF7 plugin, my contact forms stopped working. On submit, it would spin continuously. Never got an error message, no success message, no email. I rolled back to WP 4.8 and plugin 4.8 to get the forms to work again. I’ve been watching this support forum for similar threads and the response has been, overwhelmingly, to switch to the default theme or disable all other plugins. I tried disabling all other plugins, it did not help. This is a business website so I can’t just switch themes on the live site and, even if it did fix it, I certainly can’t leave it on the default theme. So while this is a decent troubleshooting suggestion, it gets us no closer to a reason or a fix for the issue.

So my question is, how else can you help? Is it a bug that needs fixed in the plugin? Or is it a bug with WP 4.8.1? Because at this point, I need to do the update to WordPress but it would require that I find a new plugin and re-create at least 10 forms.

The page I need help with: [log in to see the link]