Problem with the Newly added dropdown menu

[vijaypolimeru]

Summary

The newly added bootstrap 4.2.1 (BS4) dropdown menu is going behind the BS4 card.

Motivation

The motivation behind adding a drop-down menu is to strategically organize the content,

Drawbacks

I have added a (BS4) dropdown menu to the so-simple theme. However, it is not working as excepted, I raised a similar issue here some time back, the developer Mr. Mmistakes suggested to add the following to css in .site-nav,

.site-nav {
  position: relative;
  z-index: 2000;
}

I did that, but it did not resolved the probelm. The exact problem I am facing can be viewed here, upon clicking, the newly added BS4 dropdown menu is somehow it is going behind the BS4 card. I tried with z-index, postions etc. Surprisingly, when I reduce the screen size to mobile size it is coming as expected (i.e. dropdown is opening above the card), even if I go back to original screen it works as expected. However, when I refresh the browser, then the dropdown menu is going behind the card. Can anyone help me resolve this problem