CB List search no longer working for dropdown or checkbox fields under Joomla

We have a site that is running CB 2.1.2, CB Subs 4.1.0 and was at Joomla 3.6.5. We have now upgraded it to Joomla 3.7.2. After doing this upgrade, the CB List search is no longer working for dropdown fields or checkbox fields. When you do the submit it goes to the 404 error page. These type of searches were working before the upgrade to 3.7.2.

Go to: www.staging.stuntlist.com/west/member-search . Change any dropdown box value or click any checkbox and then Submit. The error page comes up. If you put something in the text fields (first name or last name) the search works properly.

Any idea what is needed to get the dropdown and checkbox searches working again?

Thank you

The POST is responding with a 302, which is a moved header. Do you have Joomlas redirect component in use and maybe a redirect configured for it or a redirect in htaccess? Strange that it only affects select or checkbox fiels.

The redirect plugin is disabled on the site.

I don't see anything in .htaccess that would be doing the redirect.

Only change was upgrading to J3.7.2 nothing else was changed.

Thanks

Try disabling 3rd party extensions one by one to see if any are conflicting. Aside from that I've no idea. Something is intercepting the POST and redirecting away.