And nice catch! Yes, the synthesizer does have some issue in browsers other than Chrome. I'm working on that.
Thanks again! I really appreciate it!
If I can give another suggestion: I think it would be much more useful for beginners to see the common alias of the chord in the main table (maybe below the name that already exists?).
(This is wrong, see the reply below:) For example, a beginner may see "G7" in the wild and not know it's a G minor 7 (and not a G major 7). They'd have to click the chords and search the alias list. If "G7" was written below "G minor 7", it would make things much easier.
Also, I think it would look better if the names in the main table were a bit more consistent. For exmaple, you have "G major ninth" but "Gmaj13". I think it would be better to have them as "Gmaj9"/"Gmaj13" or "G major ninth"/"G major thirteenth".
Still, I think it would be much more useful to consistently have the chord abbreviations in the main table.
Example from Google image search: https://www.musikalessons.com/blog/wp-content/uploads/2017/0... . At least this one uses maj7 for major 7, rather than M7 or △7 :)