the media library copied during cross builds is the desktop/Intel version. This is probably just because the copy is not properly qualified.
ddhill@ddhbld:~/Downloads/hf$ file jre/lib/arm/*
jre/lib/arm/libdecora-sse.so: ELF 32-bit LSB shared object, ARM, version 1 (SYSV), dynamically linked,
not stripped
...
jre/lib/arm/libjfxmedia.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, not stripped
ddhill@ddhbld:~/Downloads/hf$ file jre/lib/arm/*
jre/lib/arm/libdecora-sse.so: ELF 32-bit LSB shared object, ARM, version 1 (SYSV), dynamically linked,
not stripped
...
jre/lib/arm/libjfxmedia.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, not stripped