Have you tried rebooting with the drive in the USB slot?
I have a similar USB stick in FAT32 format that's 32gb total.
I find the (almost) ONLY way I can mount it read-write in 10.12 Sierra or 10.13 High Sierra is to reboot the machine with the drive inserted. If I insert the drive after the machine has booted it will always mount read-only.
There's no physical switch for disabling the read, but I suspect that somewhere Mac OS thinks that switch is enabled and somehow it doesn't check when it's booting. I did manage to remount it read-write as shown below, but rebooting (though frustrating) behaves better and feels safer than doing it the other way and getting messages about it being damaged.
The only other odd thing about the USB stick is that it has one USB A side and one Micro-USB OTG side. Only one side can be used at a time, both access the 32Gb FAT32 storage. I'm using the USB A side in the Mac. I wish they made these with A and C sides.
Well, I was able to mount it read-write with the following terminal fun, but after mounting it I got a dialog that said Repair failed, unable to repair this drive, it has been mounted read only for you to retrieve files from it, but you will not be able to write to it.
And then I could write to it. But it was kind of upsetting.
lamblincl5116:~ lamblin$ sudo df
Password:
Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on
/dev/disk1s1 976695384 602657408 368466424 63% 2088422 9223372036852687385 0% /
devfs 374 374 0 100% 648 0 100% /dev
/dev/disk1s4 976695384 4194344 368466424 2% 2 9223372036854775805 0% /private/var/vm
map -hosts 0 0 0 100% 0 0 100% /net
map auto_home 0 0 0 100% 0 0 100% /home
/dev/disk2s1s10 62980000 15263712 47716288 25% 0 0 100% /Volumes/LAMBLIN
lamblincl5116:~ lamblin$ diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.3 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_APFS Container disk1 500.1 GB disk0s2
/dev/disk1 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +500.1 GB disk1
Physical Store disk0s2
1: APFS Volume Macintosh HD 308.6 GB disk1s1
2: APFS Volume Preboot 22.9 MB disk1s2
3: APFS Volume Recovery 520.8 MB disk1s3
4: APFS Volume VM 2.1 GB disk1s4
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *32.3 GB disk2
1: Windows_FAT_32 32.3 GB disk2s1
lamblincl5116:~ lamblin$ sudo gpt show -l /dev/disk2
start size index contents
0 1 MBR
1 95
96 63012768 1 MBR part 12
lamblincl5116:~ lamblin$ diskutil unmount /dev/disk2s1
disk2s1 was already unmounted
lamblincl5116:~ lamblin$ sudo mount -w -t msdos /dev/disk2s1 /Volumes/LAMBLIN
mount_msdos: /dev/disk2s1 on /Volumes/LAMBLIN: Resource busy
# Here I realized that the device name was unusual.
lamblincl5116:~ lamblin$ sudo umount /dev/disk2s1s10
umount(/Volumes/LAMBLIN): Resource busy -- try 'diskutil unmount'
lamblincl5116:~ lamblin$ diskutil umount /dev/disk2s1s10
Volume LAMBLIN on disk2s1s10 unmounted
lamblincl5116:~ lamblin$ sudo mount -w -t msdos /dev/disk2s1s10 /Volumes/LAMBLIN
mount: realpath /Volumes/LAMBLIN: No such file or directory
lamblincl5116:~ lamblin$ mkdir /Volumes/LAMBLIN
mkdir: /Volumes/LAMBLIN: Permission denied
lamblincl5116:~ lamblin$ sudo mkdir /Volumes/LAMBLIN
lamblincl5116:~ lamblin$ sudo mount -w -t msdos /dev/disk2s1s10 /Volumes/LAMBLIN
mount_msdos: /dev/disk2s1s10 on /Volumes/LAMBLIN: Permission denied
lamblincl5116:~ lamblin$ sudo mount -w -t msdos /dev/disk2s1 /Volumes/LAMBLIN
# This is when I got the Unable to be repaired dialog box
# I wrote files to it in the finder, and pressed eject in the finder.
lamblincl5116:~ lamblin$ sudo umount /dev/disk2s1
umount: /dev/disk2s1: not currently mounted
lamblincl5116:~ lamblin$ ls /Volumes/
Macintosh HD Preboot 13 Preboot 19 Preboot 24 Preboot 3 Preboot 35 Preboot 40 Preboot 46 Preboot 7
Preboot Preboot 14 Preboot 2 Preboot 25 Preboot 30 Preboot 36 Preboot 41 Preboot 47 Preboot 8
Preboot 1 Preboot 15 Preboot 20 Preboot 26 Preboot 31 Preboot 37 Preboot 42 Preboot 48 Preboot 9
Preboot 10 Preboot 16 Preboot 21 Preboot 27 Preboot 32 Preboot 38 Preboot 43 Preboot 49
Preboot 11 Preboot 17 Preboot 22 Preboot 28 Preboot 33 Preboot 39 Preboot 44 Preboot 5
Preboot 12 Preboot 18 Preboot 23 Preboot 29 Preboot 34 Preboot 4 Preboot 45 Preboot 6