Cannot get or set service tag

```
➜ libsmbios git:(master) sudo smbios-sys-info --trace -v --service-tag --set=5WK2M53
ENTER SmbiosTable()
ENTER __init__(, 1, )
ENTER _errorOnNullPtrFN(, <_FuncPtr object at 0x7f6252e4a800>, (1,), )
RAN CTYPES FUNCTION: smbios_table_factory
LEAVE _errorOnNullPtrFN -->

LEAVE __init__ --> None

LEAVE SmbiosTable -->

Current tag value:
ENTER _freeLibStringFN(, <_FuncPtr object at 0x7f6252a58d00>, (), )
RAN CTYPES FUNCTION: sysinfo_get_service_tag
LEAVE _freeLibStringFN --> ''

Service Tag:

Setting new tag value: 5WK2M53
ENTER set_service_tag(b'5WK2M53', None, None, )
LEAVE set_service_tag --> -1

➜ libsmbios git:(master) sudo smbios-sys-info-lite
Libsmbios: 2.4.3
System ID: 0x097D
Error getting the Service Tag: unknown error
Asset Tag: ASSETTAG02
Product Name: XPS 15 9500
BIOS Version: 1.12.0
Vendor: Dell Inc.
Is Dell: 1
OEM String 1: Dell System
OEM String 2: 1[097D]
OEM String 3: 3[1.0]
OEM String 4: 12[www.dell.com]
OEM String 5: 14[1]
OEM String 6: 15[0]
```

I dual boot Windows and Linux on a XPS 15 9500. They are on separate drives:
```sh
➜ ~ git:(master) ✗ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
nvme1n1 259:0 0 953.9G 0 disk
├─nvme1n1p1 259:1 0 512M 0 part /boot
├─nvme1n1p2 259:2 0 34G 0 part [SWAP]
└─nvme1n1p3 259:3 0 919.4G 0 part /
nvme0n1 259:4 0 238.5G 0 disk
├─nvme0n1p1 259:5 0 16M 0 part
└─nvme0n1p2 259:6 0 238.5G 0 part
```

After updating my Arch install about a month ago my service tag was unset. Every time I boot the fans run at 100% and I see a message that the BIOS is in manufacturing mode and the service tag needs to be set. Whenever I click "Apply" after setting the service tag in the BIOS the tag disappears and it doesn't save. I tried updating and later resetting the BIOS all to no avail.

Is there a way for me to workaround this? I'm tired of having to press "Alt+F" twice when booting to have the fans not run at 100%.