After some investigation, I believe I have pinpointed the root of your issue - it seems to be related to a browser extension.
I noticed that your conversion box displays correctly on my personal laptop but not on my work laptop. This led me to suspect that there may be a conflict with a script and a browser extension. To confirm this, I tried accessing your site in an incognito window and lo and behold, it worked without any issues. The next step was to identify which specific extension was causing the problem, and for me, it turned out to be LastPass (as my work requires us to use LastPass).
If you have LastPass enabled as an extension, try disabling it and testing the conversion box again.
Additionally, addressing these console errors would be beneficial:
Uncaught SyntaxError: Unexpected token ; (index):476
carouFredSel: No element found for "#foo1". jquery.carouFredSel-6.2.1.js?ver=3.8.3:4232
Uncaught ReferenceError: paginateVal is not defined cgview.js?ver=3.8.3:28
Potential Solutions
Regrettably, there may not be much you can do about how individual extensions affect your site's functionality. If this feature is crucial for you, consider exploring alternative implementations that don't clash with common extensions (the easier route).
Alternatively, you could delve into the code of the plugin/script responsible for the conversion box to identify and resolve any conflicts (more challenging).
The most difficult option would involve examining the source code of the LastPass extension to pinpoint the bug that hinders other scripts from running smoothly. Personally, I have encountered issues where LastPass interfered with JavaScript execution in the past.