Managed to fix it.
Not required, but worth a check before next steps, do a System File Check (
https://support.microsoft.com/en-us/topic/use-the-system-file-checker-tool-to-repair-missing-or-corr...)
Download and run "Armoury Crate Uninstall Tool V2.1.5.0" - That seems to nuke everything (including, for me, the windows store version I originally installed and everything associated)
Once that has finished, download (from ASUS site, not windows store): ArmouryCrateInstaller_3.2.3.0
Run that, will take a little time, once done, it does not ask, but just do a restart.
Once restarted if you search in start "Armoury" then the apps show as "new", straight away lighting reverted to how it used to be, no delay, no errors, everything is working again...