The silly Chinese manufacturer must have installed the wrong bootloader on them. With such a basic mistake that a hobbyist with a couple months of experience would even know not to make, it's hard to have much confidence in the quality of their hardware.
How should I make it be detected as UNO instead of pro?
You would do that by doing a Tools > Burn Bootloader with Tools > Board > Arduino/Genuino Uno selected. That will have the benefits of:
- Freeing up 1.5 kB of program memory.
- Allowing you do use the watchdog timer to reset the ATmega328P without the board going into an endless reset loop.
- Making uploads a little faster.
However, if you've already struggled with the Burn Bootloader process, you might prefer to just use your boards as they are so you can get on with the fun stuff instead of getting frustrated by the fairly advanced project of burning the bootloader. They will work fine for most purposes as they are. If you do ever end up running into not having enough program memory or wanting to use the watchdog timer, you can have another go at Burn Bootloader then.
That's not to say that Burn Bootloader is impossible. For me, it's as easy as making the connections between the boards and pressing the button. I do it all the time. But for some reason the process gives a tremendous amount of trouble to some people.