That's curious. My first thought was that you should go to the dealer where you bought the router and explain the situation. I think it would be worth it to try a different router of the same brand and model. Or you could just exchange it for a more well known (aka reputable) brand. Of course, that's your call.
Here's the standard advice to improve the WiFi signal with the B2:
To improve your signal strength, try the following:
Move your B2 closer to your router.
Switch the WiFi dongle to USB C.
Move your WiFi dongle to the end of a USB extension cable.
You can buy a new WiFi dongle that has an antenna. Look for one that has the RT5370 chipset.