Missing letters - garbled fonts

[Linee]

I'm noticing missing letters and garbled text much of the time, mostly with update manager in KDE 18.2. This was also a huge problem for me in 18 with Cinnamon on this laptop and almost drove me away from Mint altogether on this machine until 18.1 came along a ran almost perfectly. My main machine is running Cinnamon 18.2 with no problems and had tried out Xfce on this one for bit without this particular issue. I've used KDE in the past but never had this problem. I'm just wondering if anyone else is experiencing this?

missing-p-8-8-17.png

inxi -Fxz
System: Host: slm-HP-Pavilion-x360-Convertible Kernel: 4.10.0-27-generic x
86_64 (64 bit gcc: 5.4.0)
Desktop: KDE Plasma 5.8.7 (Qt 5.6.1)
Distro: Linux Mint 18.2 Sonya
Machine: System: HP (portable) product: HP Pavilion x360 Convertible v: Typ
e1ProductConfigId
Mobo: HP model: 81A2 v: 49.28
Bios: Insyde v: F.27 date: 06/06/2017
CPU: Dual core Intel Celeron N3060 (-MCP-) cache: 1024 KB
flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 6400
clock speeds: max: 2480 MHz 1: 2195 MHz 2: 1257 MHz
Graphics: Card: Intel Device 22b1 bus-ID: 00:02.0
Display Server: X.Org 1.18.4 drivers: intel (unloaded: fbdev,vesa)
Resolution: 1366x768@59.99hz
GLX Renderer: Mesa DRI Intel HD Graphics 400 (Braswell)
GLX Version: 3.0 Mesa 12.0.6 Direct Rendering: Yes
Audio: Card Intel Device 2284 driver: snd_hda_intel bus-ID: 00:1b.0
Sound: Advanced Linux Sound Architecture v: k4.10.0-27-generic
Network: Card: Realtek RTL8723BE PCIe Wireless Network Adapter
driver: rtl8723be port: 2000 bus-ID: 02:00.0
IF: wlo1 state: up mac: <filter>
Drives: HDD Total Size: 500.1GB (3.9% used)
ID-1: /dev/sda model: WDC_WD5000LPCX size: 500.1GB
Partition: ID-1: / size: 89G used: 15G (18%) fs: ext4 dev: /dev/sda6
ID-2: swap-1 size: 4.11GB used: 0.00GB (0%) fs: swap dev: /dev/sda
7
RAID: No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors: System Temperatures: cpu: 51.0C mobo: 46.0C
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 195 Uptime: 5:35 Memory: 1780.6/3778.2MB
Init: systemd runlevel: 5 Gcc sys: 5.4.0
Client: Shell (bash 4.3.481) inxi: 2.2.35