Issue with a Makefile where one subdirectory isn't getting compiled

I find that in this Makefile, the EventProducers subdirectory is just not getting compiled although it is similiar in every respect with the other subdirectories. It was added newly. Any reason why the Makefile wouldn't compile this specific folder. Make clean and make has been tried already.

include $(ROOTDIR)/$(PROJECT)/abc/defines.mk
include $(ROOTDIR)/$(PROJECT)/def/xyz/delta/defines.mk

local = alpha/Services/Recording

subdirs = Factory EventProducers Search Control Control Serial

INCLUDE_DIRS += -I$(ALPHA_HOME)/Services/Recording

LOCAL_OBXS = \
        $(addprefix $(localobx)/, \
        RecordingBase.o \
        )

LIBS := $(libdir)/libalpha_recording.a
$(LIBS): $(LOCAL_OBXS)

include $(ROOTDIR)/$(PROJECT)/Build/rules.mk