Suddenly got
SQLSTATE[HY000]: General error: 1835 Malformed communication packet (SQL: select * from tb_users where (username =
tb_users
username
MariaDB just released an upgrade that fixes the issue for those who cannot run their application on PHP >= 7.3, source: https://mariadb.org/mariadb-10-5-8-10-4-17-10-3-27-and-10-2-36-now-available/