I sent two messages while wifi was not working, the first message was shown (sending in progress) but the second wasn’t, I went back to the home screen, which was empty for a moment, then when android passed from wifi to to mobile data everything went back and the missing message appeared.
Debug log: https://debuglogs.org/75be55ce835a20e623c2b27c7cacf350a0a239d0ab7ceecd8669ed000509fc30