4 GB RAM limit

[Der Geist der Maschine]

One odd thing I have noted is that ARM 64 Linux distros seem to use less memory than a AMD 64 type. It's possible that the ARM 64 instruction set is simply more compact that AMD 64.

In the past, you have been running the default Debian with its 32 bit userland. Are you comparing by any chance a 32 bit ARM userland with a 64 bit x86 userland?