לִשְׁפוּפָ֕ם מִשְׁפַּ֖חַת הַשּׁוּפָמִ֑י לְחוּפָ֕ם מִשְׁפַּ֖חַת הַחוּפָמִֽי׃
Von Sesufam das Geschlecht Sufami; von Hufam das Geschlecht Hufami.
Rashi on Numbers
לשפופם OF SHEFUFAM - he was identical with Muppim, but was so called also after Joseph because Joseph became enfeebled (שפוף) through his sufferings among the nations.
Siftei Chakhamim
Being humbled among the nations. שפוף ["humble"] has the connotation of hovering [just above the ground].