Problem running make - Syntax error: "(" unexpected

Ubuntu 18.04.4 LTS - Linux 5.3.0-28 - gcc 7.4.0

I'm trying to run make, and I get the following output:

/bin/sh: 1: Syntax error: "(" unexpected
Makefile:1699: recipe for target 'modules' failed
make: *** [modules] Error 2

I tried adding SHELL := /bin/bash to the top of the makefile.

Then I get the following.

/bin/bash: -c: line 0: syntax error near unexpected token `('
/bin/bash: -c: line 0: `make ARCH=x86_64 CROSS_COMPILE= -C /lib/modules/5.3.0-28-generic/build M=/home/dubsta/Downloads/Archer T9UH(EU&US)_V2_170831_Linux/linux_T9UH  modules'
Makefile:1700: recipe for target 'modules' failed
make: *** [modules] Error 1

The first few lines of the Makefile look like this:

SHELL := /bin/bash
EXTRA_CFLAGS += $(USER_EXTRA_CFLAGS)
EXTRA_CFLAGS += -O1
#EXTRA_CFLAGS += -O3
#EXTRA_CFLAGS += -Wall
#EXTRA_CFLAGS += -Wextra
#EXTRA_CFLAGS += -Werror

I've double checked that the kernel headers for the Linux version I'm using are installed.