Tab not open next to current via popup menu

[ReporterX]

Firefox 66.0.3 (64-bit) Conex 0.9.7

Simply open the popup menu of Conex. Select to create a new tab in any container. Expected: The tab should be opened next to the active tab that I selected. (I have set browser.tabs.insertAfterCurrent as true) Actual: it opens after the very first tab, that is at the second position of the tabs bar.