WIFI Router (R6350)

Hello, allow me to introduce myself. I disabled, and I'm not very Tech Savvy!

I generally need help from someone when I need to physically check thing on my PC equipment. 

  This is that I currently have:

WIFI Router (R6350)  AC1750) Dual-Band WiFi Router (up to 1.75Gbps) with MU-MIMO.

I bought it back in 02/2022. Being disabled, I had someone else install it for me, BUT,

I failed to register it! Anyway, this is the issues for my router....

**Right now, my laptop is in a bedroom right above a sun-room, where this router is, and I have NO issues at all as far as reception. 

**The problem is, that I need to use another Chromebook, that is located in my kitchen,

on another level of my home, and no matter what I have tried with this pc, stationed in my kitchen, is that the reception from the router to my pc (stinks), to say the least! It;s like I'm

using 'dial-up' again!

**It's so frustrating, that anytime I try to use this in the kitchen, I end up...."not using it at all because of this problem"! 

**I bought this because I was told that the Reception Range is Very far! For me, it's not working. This other pc in my kitchen is less than 20 yards away from the router.

**What may be going on here? Do I need to adjust the direction of the antennas? Do I need to do anything in the back panel with all the ports, etc.? 

**Note, that it's not my Chromebook because it worked great when I tested it out in my bedroom, just above the router loc.

**I Need Help. What option can I try now for me to get good reception in my kitchen?

Thank so much for anyone addressing this for me.