for what I remember this bug was caused by a problem of inheritance on the animation time.
It should be fixed in the latest version: please update.

If you're still experiencing the problem: just inherit everything for the theme option at survey level, and change the setting at global settings
(as a temp fix)

OK...

I am already running 3.0.5+180118, which is the latest released. And I was already fully inherited, so that did not fix.

But your commented pointed me in the correct direction to narrow things down more.

I was able to determine that the problem only happens when using the Fruity theme. It does not happen with Vanilla or any of the other default themes.

So the issue is something that changed with Fruity between 3.0.1+171228 and 3.0.5+180118 .

thank you for that feedback snowman.
if you have debug mode on, could you please check that you refreshed your browser cache (or test the survey in a private windows)?

I did not have js debug mode on before, but just enabled it. I saw no change when testing in a private window (and fully refreshed) with or without debug.

Unfortunately, troubleshooting js is not something that I know anything about.

The test sample is still active at http://survey.tjsnow.com/index.php/621661?token=Hm9rkdp5W8KznIn&newtest=Y&lang=en

thank you for that link, very useful

So, first, I can reproduce on firefox.
Then, options are set correctly, for further reference:

        .radio-item input[type="radio"]:checked + label::after{
        animation-name: zoomIn;
        animation-duration: 0.3ms;
        animation-fill-mode: both;
    }

seem deeper than expected: https://github.com/daneden/animate.css/issues/269

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=26202

Version 3.1.0 released