Question on import/export restrictions on certain products

I was thinking of building some sort of toy for my nephews, a cube or ball that would change color and perhaps make sounds when turned or rolled, and could be programmed to have various modes. I figured that accelerometer or inclinometer devices would likely be too expensive or bulky, so I initially thought of designing my own crude mechanism using a metal tube and ball with sensors at either end.

But then I found out about the MPU-6050 Gyroscope+Accelerometer board, which is available on eBay from Asian vendors for under $1.50 and uses Arduino-compatible logic and power levels and I2C. So I decided to order one to play around with. But when I went to the order page, a warning popped up saying that this item was subject to a US export restriction.

I figured that since I live in the US and was trying to import the product to the US and not export it from here, I'd be ok, and sure enough it let me place an order for the board (which I verified went through since my credit card was charged).

But it's been several days and it still hasn't shipped, which in my experience never happens, as everything I've ever ordered on eBay from Asia ships either that day or the next. So I figure that this export restriction is the reason, and either there will be a delay but it'll end up getting shipped (and perhaps held at customs and perhaps never delivered to me), or the order will be cancelled because of this restriction, or it'll stay pending forever.

Does anyone know how this works? Do "export" restrictions to the US (or any other country) also tend to apply to when you're importing an item (perhaps because the figure that once you have it, you can then illegally import or smuggle it, especially given how small and innocuous-looking it is)?

It's also available from US-based vendors, but for a lot less, and budgetary constraints force me to go with eBay for most of my electronics these days.

Btw, could this also be a Trump thing, perhaps due to tighter controls on imports and exports since he took office, especially from China?

Are there FAQs or previous threads that deal with this topic, as I assume that it affects a whole range of devices and people?