It seems, in the US, names with ei coming from German are pronounced /aɪ/ (Lye ber) but names with ei coming from Yiddish are pronounced /i/ (Lee ber).

When I was young, the composer-conductor Leonard Bernstein had his name frequently pronounced both ways, depending on the background of the person pronouncing it. There was some comic with a routine about Albert Einstein pronouncing the name in the Yiddish way for effect.

It seems, in the US, names with ei coming from German are pronounced /aɪ/ (Lye ber) but names with ei coming from Yiddish are pronounced /i/ (Lee ber). According to user's answer, Fritz Leiber (of German ancestry) used the German-type pronunciation.

When I was young, the composer-conductor Leonard Bernstein had his name frequently pronounced both ways, depending on the background of the person pronouncing it. There was some comic with a routine about Albert Einstein pronouncing the name in the Yiddish way for effect.