Telegram has banned the usage of "star" characters in names since premium(paid) users will get a star icon with their name, including channel/group names.

Telegram 已禁止在名称中使用“星号”字符，因为高级（付费）用户将获得带有其名称的星形图标，包括频道/组名称。

Example: ⭐☆★
频道投稿：@zaihuabot
交流群组：@zaihuachat
花花优券：@zaihuatb