I love AC's, and currently run three of them. However, two of them have now had an issue with restarting after turning the power off for maintenance. For one of them, this is a 50/50 shot every time I unplug it, and I have to fiddle with it for a bit to get it to restart. For the other, it happened for the first time after an extended period of constant running (2+ months), and, as it was late, I let it go till morning. But it restarted on its own several hours later.
As much as AC's are commonly considered the gold standard in HOB's, this is not an uncommon issue with them. Next time (after using AC's as the last 5 HOB's I've used), I might try something new.