Concatenated SMS messages are silently dropped

purple-mm-sms seems to silently drop messages that are too long to be sent in a single SMS. Neither Chatty nor Pidgin show them, while short messages being sent before and after concatenated ones are delivered without any issues.

Launching modem-manager-gui afterwards shows that the message got delivered by the modem with no issues.

Sending concatenated messages works fine; it's just receiving that doesn't work.