I tried both phrases mentioned. With the both, it matched what I expected and not other cases. Can you give specific examples of what content matched but wasn't supposed to or didn't match but should have?
ＷＥWE７９ - added a spam-phrase. Okay, it doesn't pass.
ＷeＷe7９ - Not added to the spam-phrase, it skips.
Outwardly they differ, but the phrase is one and the same. So they both blocked, you need both to add them to the spam filter.
If we add the first phrase, the second is not blocked. Is this normal?
Sorry for my english.
Yes, they're not really the same characters, even if you resolve upper and lower case. There are "full width" Latin character versions there which won't be considered the same as regular Latin characters.