The things to look up are Beta Israel (a lost tribe who were discovered in Ethiopia) and Operation Solomon (how they wound up in Israel). From there, you might find some answers from Israeli sources or elsewhere. I’ve similarly heard this assertion/rumour that the women of Beta Israel were sterilised after their incredible discovery and rescue, but haven’t seen authoritative sources for either side. Still, this should be an interesting rabbit hole to go down.
Sounds about right. (please forgive the link to the other place)