Hookthreory Book I - Section 2.2 Basic Chord Function - Broken play buttons

bug reports
1

Hooktheory Book I
Section 2.2 Basic Cord Function

Play buttons are broken:-

Basic Chord Structure
Repeating Four Chord Progression

Windows 11 - Chrome Version 101.0.4951.54 (Official Build) (64-bit)
(same in installed app as well)