So far all browsers on today's current crop of Smart TVs show issues with what you noted as well as video streaming. So far the makers have shown little interest in fixing it.
If you feel this is a reason to return, do that quickly but be aware other models have yet to work much better.
I recently purchased a (LG) lg43uh661v smart TV. It allows access to the internet and therefore Facebook. I entered my login details and all worked well. Now I try a second time and the web page remembers my email address but I can find no way of selecting it. So I have to re- enter everything.
Anyone have any ideas?