I'm afraid it is. Let me tell you, I love Harbor Freight. I have half a shop full of their tools, and had a good tumbler from them. It had an orange bowl, and worked as well as any other tumbler, for the last year or so. Then something happened, and the threaded shaft kind of stripped, and wouldn't hold the wing nut on sufficiently, so the bowl turned and came completely loose. I took it back, and at that time the only tumblers they had were like yours, with the blue bowl. I went through 4 of them, before I finally got ahold of their technical support folks, who told me that they were aware of the problem, and thought their supplier had fixed the issue. Perhaps you are one of the extremely fortunate ones that has a solid model, but all 4 that I got had the same problem. They would only tumble for ~ 1 hour, then they would shut down because their motors overheated. Once they cooled down, they would start back up again.
If you can tumble for 2-3 hours without any issue, then you probably have a good one. I just got tired of going through the local store's inventory, and decided to get a refund. I purchased a Frankford Arsenal unit on MidwayUSA for $30.00, and have been very happy with it.
By the way, if it costs more than $20.00 at Harbor Freight, you may be better off purchasing an extended warranty. It came in very handy in my case.