I found the issue was with the theme.
I’m using a standard theme “LightBlue” only with modified shade of blue for primary color.
.badge class is white on white.
and the class doesn’t even contain a background-color setting (there used to be a background color previously)
v2022This thread pointed me in the right direction: Detail record count is white on a light grey button - #4 by arbei solved the issue by adding background-color to the .badge class in custom css: