Screen is not locking OR shutting off according to set timers

[kentchristopher]

I've left my laptop unattended for well past the set timer limits, and every time I come back to it the screen is on and unlocked, as if the energy saving and screen lock settings have no effect. Anyone know what this might be? Kernel issue maybe?

Output of 'inxi -Fxz'

System: Host: X230K Kernel: 4.13.0-41-generic x86_64 (64 bit gcc: 5.4.0)
Desktop: KDE Plasma 5.8.9 (Qt 5.6.1) Distro: Linux Mint 18.3 Sylvia
Machine: System: LENOVO (portable) product: 232035U v: ThinkPad X230
Mobo: LENOVO model: 232035U
Bios: LENOVO v: G2ETB1WW (2.71 ) date: 03/09/2018
CPU: Dual core Intel Core i5-3320M (-HT-MCP-) cache: 3072 KB
flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 10376
clock speeds: max: 3300 MHz 1: 1197 MHz 2: 1202 MHz 3: 1204 MHz 4: 1410 MHz
Graphics: Card: Intel 3rd Gen Core processor Graphics Controller bus-ID: 00:02.0
Display Server: X.Org 1.18.4 drivers: intel (unloaded: fbdev,vesa)
Resolution: 1366x768@60.02hz
GLX Renderer: Mesa DRI Intel Ivybridge Mobile
GLX Version: 3.0 Mesa 17.2.8 Direct Rendering: Yes
Audio: Card Intel 7 Series/C210 Series Family High Definition Audio Controller
driver: snd_hda_intel bus-ID: 00:1b.0
Sound: Advanced Linux Sound Architecture v: k4.13.0-41-generic
Network: Card-1: Intel 82579LM Gigabit Network Connection
driver: e1000e v: 3.2.6-k port: 6080 bus-ID: 00:19.0
IF: enp0s25 state: down mac: <filter>
Card-2: Intel Centrino Advanced-N 6205 [Taylor Peak]
driver: iwlwifi bus-ID: 03:00.0
IF: wlp3s0 state: up mac: <filter>
Drives: HDD Total Size: 384.1GB (46.9% used)
ID-1: /dev/sda model: SAMSUNG_MZNTY256 size: 256.1GB
ID-2: /dev/sdb model: M4 size: 128.0GB
Partition: ID-1: / size: 25G used: 16G (66%) fs: ext4 dev: /dev/sda3
RAID: No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors: System Temperatures: cpu: 55.0C mobo: N/A
Fan Speeds (in rpm): cpu: 3298
Info: Processes: 327 Uptime: 1 day Memory: 11982.4/15740.8MB
Init: systemd runlevel: 5 Gcc sys: 5.4.0
Client: Shell (bash 4.3.481) inxi: 2.2.35