i18n in html comments returns a nested translatable error

[fireworkz]

with template markup as:

<div *ngIf="tData" class="theme-detail__masthead">
<!--  i18n    <div>
        ...
    </div>
 -->

    <div class="headerblock">
        <h3 class="header header--panel">{{tData.sectionText}}</h3>
        <p class="strapline" i18n="theme detail intro - header">foo bar</p>
    </div>

</div>

xi18n triggers the following:

Could not mark an element as translatable inside a translatable section

<!-- i18n on line 1 is the culprit, however the error is flagged on line <p class="strapline" i18n="theme detail intro - header">foo bar</p>

changing the first line to <!-- needs i18n <div> prevents the error from being flagged

[fetis]

any progress on it?