Was thinking about this one? https://www.amazon.com/StarTech-Gigabit-Ethernet-Network-Adapter/dp/B0095EFXMC
edit: apparently the TV is missing drivers according to this thread: https://community.sony.com/t5/4K-Ultra-HD-TV/x85d-x8500d-Unable-to-Use-USB3-to-Gigabit-Ethernet-Adaptor/td-p/622738
Couple brands I've used in the past with success were Inateck and Vention.
The inateck one was more expensive (like $30 CAD) but it also included 3 USB ports as well as the ethernet adapter.
The vention one I bought directly from China for like $11 CAD.
Great speeds on both devices.
I have tried USB to ethernet adapters on my Bravia 800D with no luck -
Apple USB Ethernet Adapter
https://www.apple.com/shop/product/MC704LL/A/apple-usb-ethernet-adapter
Plugable USB 2.0 to 10/100 Fast Ethernet LAN Wired Network Adapter
https://www.amazon.ca/gp/product/B00484IEJS/
Plugable USB 2.0 to 10/100/1000 Gigabit Ethernet LAN Wired Network Adapter
It would be great if we could compile a list of working vs non-working USB to ethernet adapters - unfortunately, I haven’t come across one that actually works on my Bravia.
Your tv doesn't come with an Ethernet port?