I just finished setting up a custom router with dns ad blocking. Next comes a media player so I can purge this smart TV filth from my household.
Huge shout out to Louis Rossmann and the FUTO communuty contributors, check out the wiki on self-hosted software if you haven’t already.
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.