Video install strange behaviour

Web Designer Premium.
I have attached a screenshot to aid my description. I hope it is clear enough to view.
I have a website that I often install MP4 video's on webpages using a "Place Holder" rectangular graphic Box. This has worked without any issues for a long time.
Now all of a sudden when installing the video HTML code into the 'web properties' HTML (body) window I get screenshot 2. (just a dotted rectangle with the widget tab). The Black rectangle disapears.
When I deselect I'm left with an empty space - screenshot3. No indication anything is there.
The good news is that when uploaded to the web all is good and video displays and functions normally. So I guess you could argue "whats the problem then". It's not really I suppose but I'd like to know whats caused it and whether I can undo the fault.

Any comments welcome.
Thank you.

Can't replicate that Joned. Can you post your Placeholder text?

Thank you Egg.
The
HTML (Body) code is.....
<iframe src="https://player.vimeo.com/video/812130368?h=af53447593&amp;title=0&amp;byline=0&am p;portrait=0&amp;speed=0&amp;badge=0&amp;autopause =0&amp;player_id=0&amp;app_id=58479" width="542" height="382" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen title="The Power of Love.mp4"></iframe>

regards
joned

Joned, your code has no problems.

Have you unticked the Re-generate placeholder image automatically option?

My code also works:

Code:

---

<iframe src="https://player.vimeo.com/video/812130368?h=af53447593&title=0&byline=0&portrait=0&speed=0&badge=0&autopause=0&player_id=0&app_id=58479" width=100% height=100% frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen title="The Power of Love"></iframe>

---

Acorn

Thank you Acorn.
I had it ticked by default so ignored it. Following your message I unticked it and reticked it and now I have the placeholder image as normal.
Thank you for pointing me in that direction.
All good now.

regards
Joned