I bought a new TV last year after my Hisense kicked the bucket and had a similar experience.
Not sure if it applies to your situation, but I just factory reset my TV, never enabled wifi, and hooked up a smart device I had lying around (Nvidia Shield). Now it all works great and if the smart functions upset me I can throw just the smart TV part in the trash and go back to my VCR.
I bought a new TV last year after my Hisense kicked the bucket and had a similar experience.
Not sure if it applies to your situation, but I just factory reset my TV, never enabled wifi, and hooked up a smart device I had lying around (Nvidia Shield). Now it all works great and if the smart functions upset me I can throw just the smart TV part in the trash and go back to my VCR.