[DRUPAL 8] Missing id and aria-labelledby in newly created menu

Drupal 8.4.2

I am using a sub theme of the bootstrap theme named ‘tvb’ but this problem seems to happen regardless of any theme I have tried, sun theme or otherwise. 

I created a custom block, and then a new page to display that block. I then created a new menu, and added it to the same new page. It displays via Panels -> Content as having a PLUGIN ID of: 


Upon inspecting the HTML output, it seems the heading_id is not being inserted within the id and aria-labelledby <nav> and <h2> elements: 


The Main navigation menu within the ‘Navigation (collapsible)’ block renders as follows: 

<nav role="navigation" aria-labelledby="block-tvb-main-menu-menu" id="block-tvb-main-menu">
    <h2 class="sr-only" id="block-tvb-main-menu-menu">Main navigation</h2>
    <ul class="menu nav navbar-nav">

However my custom menu that is within my custom Basic block renders as: 

<nav role="navigation" aria-labelledby="-menu">
    <h2 class="sr-only" id="-menu">Personal Goals</h2>
    <ul class="menu nav navbar-nav">

The id element is completely missing from the <nav>, and the aria-labelledby element only contains “-menu”. The id element of the <h2> also only contains “-menu”. Am I incorrect that I should be expecting to see something like the following: 

<nav role="navigation" aria-labelledby="block-tvb-personal-goals-menu" id="block-tvb-personal-goals-menu">
    <h2 class="sr-only" id="block-tvb-personal-goals-menu">Main navigation</h2>
    <ul class="menu nav navbar-nav">

Any insight is appreciated. 

Drupal version: 

Source: https://www.drupal.org/taxonomy/term/3/feed