Bug ? striped table (using dark transparancy) isn't working over cards

[PGTBoos]

I'm using bootstrarp 5.3.3 and made a minimal example of the problem here https://stackblitz.com/edit/7tydqk?file=index.html
In my application the card color is actually set by Angular but for the case of simplicity i made an minimal example.
The card color refers to certain modi of machinery.
With bootsrtap 4.6.2 i was able to create a striped table where some rows where slightly darkened.

Below line is a dark color but its 20% transparant and thus on a green card should show as dark green, and on a red card as dark red.
.card .table-striped > tbody > tr:nth-of-type(even) {
--bs-table-accent-bg: rgba(0, 0, 0, 0.2) !important;
}

Whatever i try the default white-lightgray table striped is shown

Any idea on how to solve this