Bluetooth issue

I just leased the 2019 Envision (trading in the 2017 lease). I had an iphone 7 and I began having issues when I used Siri in car. All was fine for about a month. Now, I push the steering wheel button and the Siri command does not connect long enough for me to do anything. Then I connected via CarPlay, and received a response from Siri, "There seems to be a software problem, try again later."
I called ONSTAR and they did a reset and told me how to reboot and disconnect and connect.That did not work. I went to Verizon and they looked at all my settings and versions and after 2 hours there, the phone/bluetooth WORKED, for about 2 weeks. I then went to the Buick dealer. A technician who I was told was VERY knowledgeable would be able to help. He said, "Nothing I can do. This is an old phone, you need to upgrade your phone." So I went back to Verizon. upgraded my phone to the "11". All is working just fine, until yesterday. I received a text, and the text notification would not stop notifying me..... It finally stopped. I went to send a text, and the first issue of not staying connected happened.
It has to be a BUICK SOFTWARE issue... Calling them again NOW. They need to look into this.