Iframe being stripped from tag description

Hi,

since few weeks, no idea when exactly, my videos hosted on streamable.com are being stripped from product tag descriptions.

I am hosting there and embedding videos of my product usage and suddenly, when saving changes to text on tag page – iframe is being truncated.

There you have code when being saved:

[su_row][su_column size="1/3" center="no" class=""]
<div class="descVidHowTo" style="width: 100%; height: 0px; position: relative; padding-bottom: 100.000%;">
<iframe style="width: 100%; height: 100%; position: absolute; left: 0px; top: 0px; overflow: hidden;" src="https://streamable.com/e/z44se6?loop=0" width="100%" height="100%" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
</div>
[/su_column]

and there it is after save:

[su_row][su_column size="1/3" center="no" class=""]
<div class="descVidHowTo" style="width: 100%;height: 0px;padding-bottom: 100.000%">

</div>
[/su_column] 

Iframes saved weeks back are working just fine. I have problems only with new tags.
I’ve tried following, but without luck: https://docs.woocommerce.com/document/allow-html-in-term-category-tag-descriptions/

Example of expected outcome: in link above, embeded iframe video is being dispalyed normally
Currently, in the place of vide there is just blank space…

please advise,
Tom

The page I need help with: [log in to see the link]