Intermittently losing keyboard input

[LWHOTD]

Have been attempting to track down an issue w/ Linux guest VM but not having any luck.

Host = Centos7 64bit w/ i5 32gb mem
Guest = Lubuntu 16.04LTS through 17.04 1gb mem single core assigned
VBox 5.1.22 w/ same version Guest Additions installed

Main form of access is VRDP initiated from a Win7 machine.
Keyboard randomly loses all input, however the mouse will function without issue and a reboot of the VM will restart of the VM will resolve temp. Issue can occur mid keystroke ( entering in an IP or name) so does not appear to be related to "slow mode" or a hotkey.

When this occurs, can go to the physical machine and outside of the running VM the keyboard works without issue.
Initially thought this was USB related, have since switched the physical host to a PS/2 KB/mouse however issue remains. Looking further into possible issues with the load itself, created a new image on the host using 17.04 and the server workaround (install server ISO, load Lubuntu-desktop) which did not resolve.

No issues when using a Windows based VM from the same Host, with the VBox logs not actually showing anything to indicate an issue when it occurs. Will attach log later tonight, strange issue...