OK – so we are seeing no reportable conflicts or errors but clearly there is some sort conflict of code going on somewhere.
Would you be able to run a couple of quick experiments for me? What would be useful for starters is if we can hone in on the js library that is causing the problem. So – if you can locate the place in the WP theme code where these js libraries are enqueued you could comment out their loading and then run the forum page to see if the quote comes back to life. Of course, either way, go back and then uncomment the code again so this does not effect the loading of the rest of your site.
If this is possible then the two js files to stop loading are firstly ‘jquery.effects.core.min.js‘ and then ‘nv-script-pack.js‘. I would suggest doing these one at a time and separately.
The aim here is simply to discover where the problem lies. If we can locate that then we can start to think of ways to work around it.
One caveat though. It is possible that stopping one of these scripts from loading may then cause an error if there are any in-line calls to use them. This could then stop other features of the form from working so keeping an eye on the error console would be helpful. I would also refresh your browser cache between each quick test.
Is this all possible? It should only take a minute or so to achieve.