Hey @Chrissie13
I would like to suggest you to contact Google Support Team as they can run diagnostics remotely and fix many issues without you sending your phone away. I have always had very good customer service from them. In the current times might take a bit longer to chat to an agent but as soon as you do they will be able to help you here. It seems to me like this is software error since it only happens when you browse the internet.
Here is the information to need to get in touch with them. When you speak to them let us know on the update on your enquiry. Hopefully they will be able to fix it for you very quickly.
Kind Regards
Gregor