His personality has become increasingly silent, just like his name, which worries and troubles the Yuan Family.
The first to be concerned was Zhang Shirou, the young Madam pregnant with the Yuan Family's eldest grandchild.
Zhang Shirou advised Yuan Chenghe to let Yuan Chengmo do what he wants and pursue the person he desires. Otherwise, if things continue this way, they'll drive him insane. Moreover, forcing Yuan Chengmo to forget Munni will only increase his fondness for her, thus having the opposite effect.
Initially, Yuan Chenghe did not agree with Zhang Shirou's opinion, but seeing that Yuan Chengmo's condition was indeed worsening, and after Zhang Shirou's repeated persuasion, he finally compromised and also convinced the other Yuan Family members.
However, the precondition was that if Yuan Chengmo was rejected by Munni, he would have to completely abandon any improper thoughts and dutifully seek another partner.