Font size problem in only one slide after viewing it on MS Office from mobile!

My sister made slides using Libre Office in Ubuntu 20.04 and saved it in pptx format.
Transferred that file in mobile > Launched MS Office (in mobile) > Opened the file (in mobile) > It showed like this:

The fonts in the tenth’s slide looked terrible.
But on the computer, it looked perfectly fine as u can see below:

I wonder what is causing this issue! Is it because of font, MS, Libre, etc? Help me.

> Mobile: Samsung Galaxy A70s Playstore
> MS Office version: 16.0.13127.20166
> Android 10

Problem is much broader than I thought:
This time, I am not even using MS office, I going to from Firefox 80 and opening this document from the sent document, and it looks like this:

Why there are those dots appearing in the documents? Where they came from? There are no such dots in the original document?

I reopened the document in Firefox from my host machine (Ubuntu 20.04), the problem is the same.

What might “viewing it from mobile” possibly mean? Is there something called “viewing from mobile” that has a universally set and standard meaning in this world?

Viewing or reading from mobile (Samsung Galaxy A70s) using MS Office. Is that clear?

Better, and then the next question is: do you realize that what you talk about is a bug (naturally, you describe that something LibreOffice generates is not working correctly when opened using reference application for that format); and then had you read what is appropriate for the Ask site, and where should bug reports go?

Mike, can u please look at my second situation where I updated the post?

Has that second situation made it any different? You are describing a bug; a bug needs a proper bug report; bug reports should go to the proper place; have you filed the report yet?

1 last question and I will fade away from here: Do you think all these issues I am having, is NOT because of LO?

To the contrary: I ask you for the third time to file a BUG report about a problem in LibreOffice.