Why can I still see blacklisted text messages?

Imperfect interception settings, mobile phone system problems.

1. Imperfect interception settings: Although blacklist interception is set, there are some loopholes or imperfect settings, resulting in blacklisted short messages still being received.

2, mobile phone system problems: Sometimes there will be some problems in the mobile phone system, resulting in blacklisted messages not being completely intercepted, so that they can still be received.