Yes, as the comment below, this name did not originate in Eastern Africa. I haven't done the research, but I'm fairly confident it existed in Europe first. Maybe someone could update that or verify it.
Only two things I associate this name with: the nut Filbert, and the squirrel from Animal Crossing.
― Anonymous User 1/29/2017
1
Filbert the Flea was an early 1950's children's show. The show consisted of a narrator drawing the title character's adventures on a pad and tearing off each page as he continued.
Sources:
https://nameberry.com/babyname/filbert
https://www.ancestry.com/name-origin?surname=filbert&geo_a=r&geo_s=us&geo_t=us&geo_v=2.0.0&o_xid=62916&o_lid=62916&o_sch=Partners
https://www.sheknows.com/baby-names/name/filbert/
http://www.thinkbabynames.com/meaning/1/Filbert
https://www.etymonline.com/word/filbert
https://www.babynamespedia.com/meaning/Filbert
https://www.thebump.com/b/filbert-baby-name