I need some clarity on the TypeError being generated for Calcite Tabs.

It seems the error is generated during the DOM rendering when the tabs are not directly visible in the DOM body, but instead in a parent element such as a calcite-panel.
The line in the module where the error occurs upon creating a new class reads as follows:
this.activeIndicatorEl.style.transitionDuration = "0s"
It seems as if the "activeIndicatorEl" property is not found.
I have created a CodePen (https://codepen.io/fcbasson/pen/KKByZzV) with two sets of tabs, of which one is within a panel. Have a look at the browser console when the DOM is rendered to see the errors popping up.