I run multiple user account in Kodi - each time i sign in to one the Update available logo in the bottom left pops up for a bit then disappears. If i manually run the update I get the no notification available.
Is this correct behavior? Not an issue just confusing. 
Yep, I suspect the MyOSMC addon service is restarting for each user, and the image gets posted to the screen before being hidden. Usually it will happen too fast to notice it, but if the system is slowed down with other things it might stay up for long enough to be noticeable.
Nothing to worry about.
Makes sense, cheers for the quick response!