Cannot execute command without /usr/bin prefix

[msequino]

Hello, I'm facing a problem which cannot allow me to launch an executable whether I don't prepend /usr/bin folder.

processManager("command", "java"); // KO

processManager("command", "/usr/bin/java"); // OK

The path is already set.

Environment info:
Lubuntu (Linux 5.11.0-18-generic)
Matlab R2021a
Java 1.8.0_202-b08 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode