.services-flex
will always be an only-child in each dyn-item, which is an odd number, so your CSS rule doesn’t apply to it.
You should nth-child the dyn-item instead:
.service-flex-master .w-dyn-item:nth-child(even) .services-flex {
-webkit-flex-direction: row-reverse;
-ms-flex-direction: row-reverse;
flex-direction: row-reverse;
}
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