Video not working on internet

Bibi69 wrote:

I found the solution !

Yep, after I found the web page has a minimum width requirement for some
of its elements.

I'm visually impaired so I set the zoom factor of Windows to 175%. I
tried to set it to 150% and everything's fine (fortunately I don't
have to close the session as in Windows 7). I don't know why it's a
problem but I know what I should do to correct it. Thank you for all
the time you spent on this.

That has to do with the width of the element, as mentioned. Reducing
the zoom means more pixels of the web page can be displayed in the same
width. In contrast, increasing zoom means the pixel width of the page
is less. Either reducing the window size or increasing zoom to the
pixel specified for the width of an object can hit its minimum size
threshold.

https://www.w3schools.com/tags/att_width.asp

If the window is not wide enough to display the element, the code can
decide to display something else, or not display the element at all.

As screen resolutions have gone up, so have expected window sizes for
web pages. I remember when sites started assuming their web page was
viewed at 1024x768 screen resolution. Some are starting to push that up
to more pixels for width (and sometimes for height) as screen
resolutions have gotten even larger ... despite many users have to
change the DPI setting to see the ever diminishing text at the higher
screen resolutions (because the physical monitor size does not increase
in proportion to the screen resolution increase). While the page could
use scrolling, many sites want a minimum width (and height) to their
elements.

In a web browser (any of them), the typical hotkey to change zoom is
Ctrl+mousewheel. That lets you quickly change the zoom level to see how
the page displays at different zoom levels (which effectively changes
the size of the window).

In Firefox, changing the zoom level will display a zoom level percentage
icon at the right ends of its address bar. After zooming in or out, you
can click on that zoom icon to reset to 100% (which is what sites will
expect for zoom level when designing the layout of their web pages).

To avoid the minimum width attribute problem you encountered when
zooming in (to enlarge the text in a web page), also enlarge the size of
the web browser's window. Don't rely on a horizontal scrollbar showing
up as you zoom in. For example, the above W3Schools web page will not
show a horizontal scroll bar no matter how much you zoom into the page.