I get high CPU an then it seems to be unstable. Openhab tried to fetch http data and try also to update items, but that get stopped after a while. CPU was 100%. After I installed the small fix, its look better now. But is Openhab rebooting itself if there is a timeout?
I have open a thread about unstable issues here: Openhab 4.0.1 unstable - #7 by Wikibear
At the moment I do more documentation. 
The interesting part is what really happen and what try to do everything that Openhab get unstable and produce this timeout.