"Loading..." message when searching KM articles


We are using SM 9.21 and I recently reployed SM into a new environment.

Everything works ok, except that when searching knowledge articles the search results appear followed by a little blue box with "Loading..." in it.  This stays on the screen for about a minute then disappears, but in the meantime you are unable to click on anything else and you have to wait for the "Loading..." box to disappear.

We did not have this issue in our previous environment.

Does anyone have any idea what might be causing this?