Answer:
While the Polo family's close relationship with Kublai Khan gave them significant advantages, it also presented some challenges and disadvantages. One disadvantage that the Polos faced was that they were seen by many in Europe as being too closely associated with the Mongol Empire.
At the time, the Mongols were considered to be enemies of Christian Europe, and many Europeans viewed the Polos' extensive travels in Asia and their close ties with Kublai Khan as unpatriotic or even traitorous. This made it difficult for the Polos to return to Venice and resume their previous lives as wealthy merchants.
Additionally, the Polos' association with the Mongol Empire meant that they were often subject to suspicion and scrutiny from European authorities, especially during times of political tension between Europe and Asia. For example, after returning from their second journey to Asia, the Polos were briefly imprisoned by Genoese authorities who suspected them of spying for the Mongols.
Despite these challenges, however, the Polos' connections to Kublai Khan ultimately proved to be a considerable advantage, allowing them to establish lucrative trading relationships and accumulate vast wealth during their travels in Asia.