One user has reported that the issue solved itself without action (which confirms it's a "weird bug", as you said). Another user has experienced the issue and managed to generate a sysdiagnose log (256 MB). What is the next step for me? Should I file an official bug report?
For orders of magnitude, I've had 5 different users reporting this issue over the past month for 10,000 installs. Assuming only one out of 10 users affected takes the time to raise a complaint (it's a free app), it happens roughly once every 200 installs.