I have a dual installation of Windows & Ubuntu and I use Google Keep Chrome app on both the OSes as well as on my Android phone. I boot into Ubuntu about once a month or so. The problem I am having is that the Keep chrome app on Ubuntu shows some older notes that I have deleted few weeks back. Those notes don't show up on other Keep apps or on keep.google.com. I expect those noted to be deleted from all Keep apps because the updated content is stored on Google's servers & all apps should be in sync. 
Google Keep sync is delayed or doesn't happen when a long time between logins
google keep