Chrome Version       : 56.0.2924.87
OS Version: 10.0
URLs (if applicable) :
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari 5:?
  Firefox 4.x:?
     IE 7/8/9:ok

What steps will reproduce the problem?
1.on  USPS.COM  when trying to purchase stamps.  Usually when you 'click' on the  FORMAT:  window, one or more options will drop down.   This does not occur when using  Chrome.
 
https://store.usps.com/store/browse/uspsProductDetailMultiSkuDropDown.jsp?categoryNavIds=buy-stamps&categoryNav=false&navAction=push&navCount=0&atg.multisite.remap=false&categoryId=buy-stamps&productId=S_119604

2.   Here, the  FORMAT:  Coil of 100 - $34.00 ( down arrow )   should, when clicked, present other formats of this stamp.  ( Pane of 20, block of 10, ect )   However, when using Chrome, and 'clicking' this box, nothing happens.

3.

What is the expected result?
Various Options should appear, to allow selections.

What happens instead of that?
Nothing happens.

Please provide any additional information below. Attach a screenshot if
possible.
  Internet explorer and microsoft edge perform as expected,  the  FORMAT:  box can be 'clicked' and drop-down choices appear.


UserAgentString: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36