When you click "Check" on the test panel in the learn page the button goes weird

[PaulKinlan]

Describe the bug
When you click "Check" on the test panel in the learn page the button goes weird

To Reproduce
Steps to reproduce the behavior:
Go to the test widget, click "Check" and then you see the next button appear, however the "Check" button has a very weird style (almost like a broken ripple effect)

Expected behavior
The check button shouldn't look like that, I would expect it to still be visible,

Screenshots
Check the bottom right.

.

[rachelandrew]

@andy-piccalilli is this another regression? It's happening on all of the courses.

[Andy-set-studio]

Yeh unfortunately it's what I call a Zombie component: half dead (from the old system) and half alive (from the new system). I'll put some sticky tape on it.