All of embanded Iframe runnung when loadinf the WP page

I have an e-learning site:
user: envato@envato.com
passw: envato
https://jachtakademia.hu/courses/3-modul/
I inserted to the site the following code:

[advanced_iframe use_shortcode_attributes_only=“true” src=“https://tavoktatas.mja.hu/12/teszt/06/index.html” width=“100%” height=“75%” id=“advanced_iframe” enable_external_height_workaround=“true” ]

This is a file of the test, made by Ispring, has a music intro.

May be from last upgrade (first half of December, the advance Iframe Pro play the music all of the other tests. Before the upgrade all of the test worked alone, ne play the intro music.

Please help me, what to do.

Thank you in advance

Tibor
tibor@mja.hu