The snap for version 4.4/stable fails with an illegal instruction signal on raspberry pi 4 when running the command juju-db.mongod --version.
Running under gdb, the failing instruction is ldaddal, that became available in armv8.1-a.
I have tested the older 4.0/stable version and it does not seem to suffer from the same problem.
The failing snap version is selected by juju 3.4.2 when bootstrapping, preventing the use of my Pi4 MicroCloud with Juju.