Who I have the same questioned this topic

I had a Samsung note 4 for years and never had any issue getting text or phone calls inside my work building. Bought a new Note 9 and can't get texts or phone calls on wifi inside my work building. We have wifi, I'm connected to the wifi with excellent signal strength and both arrows lit up and nothing comes through. The wifi provider is through AT&T. I don't get anything until I am out of my building and about 20 yards away and suddenly I will get everything I missed for the last 10 hours. I got a new sim card, I use verizon msging app, I have factory reset so many times, I have done everything possible and I am so annoyed that I pay a fortune for what is supposed to be amazing service only to not get the simplest things. I am open to trying any other solutions. PLEASE HELP!