TrueNAS-13.0-U6.2
My byhve vm is configured with 8GB RAM but it takes much more … 22GB I saw until the Truenas system was OOM
I figured the same, some time ago, on my old system (and if i remember well, was on same version): giving to VM only 2gb, It takes all RAM available, until system crash.
Now on 13.3 im not having issue anymore… Maybe Is worth try to update