A little help, please!

Hi, gang!!!

I use MuseScore 3.5.2 Portable AppImage inside a computer with Ubuntu Studio 20.04.1 LTS (64 bit Linux).

I have a problem with this specific file I'm attaching, here.

Each time I open it, Musescore takes a long time (more than 10 seconds) to start to play it.

And, it is not only when I ask Musescore plays the tune. It is the same with any Menu command I want to use: There is always a time delay, which is not normal, of course.

I wrote this file, years ago, with more than 10 Christmas pieces, but... It is the only one file I have this issue, and I don't understand what is the specific problem, here. What is the difference in this file? ???

I didn't use, and I don't know any kind of "DELAY" command into the Musescore playing part or something. So...

Can somebody help me, please?

I'm uploading the piece with 3 different format files (Musescore standard, Midi standard and MusicXML standar), just in case.

Blessings and Greetings from Chile!!!

JUAN