When I use asterisks to bold/italicize by **（** inside (right after) zenkaku text, I get the following - （, 【, { are not bolded:
INPUT
あ**（** あ<b>（</b>
い*a* い<i>a</i>
う**＜** う<b>＜</b>
え**【** え<b>【</b>
お*{* お<i>{</i>
OUTPUT
あ**（** あ（
いa いa
う＜ う＜
え**【** え【
お*{* お{
Is this a known bug or a designed behavior?
<b> </b>で挟んだらうまくいくかもしれませんが、どうでしょう？