Your problem here is the lack of “flex-children”. These would need to contain the styles to truncate an element, not the parent container.
Try moving the truncate properties to a separate .flex-child
class like so:
.flex-child {
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis;
}
Source and detailed explanation: https://css-tricks.com/flexbox-truncated-text/