Hi Trung KiênVN,
Thank you for posting in this community.
According to this article: Issues with fonts in Office for macOS (microsoft.com)
We noticed that if you have a large number of fonts installed on your system, Microsoft Office apps may not be able to load all the fonts. This causes some fonts not to appear in the font picker. You can work around this by setting the fonts you need that do not appear as prioritized fonts.
To set prioritized fonts, please kindly check the steps in the above article.
Moreover, I understand your feelings and the inconvenience caused to you. So, to address your concerns, I would suggest you send a feedback to report this issue right with in any Office app. (From your Excel app, go to Help > Feedback.) Since it is the quickest route to get your comments to the related programming developers’ ears. They read customer feedback daily.
Thank you for your time and understanding.
Best Regards,
May