People keep saying their TV does this. Can anyone recommend some Benn Jordan or Technology Connections style YT videos that conclusively replicate this?

I haven't seen an actual experiment that replicates anecdotal evidence but this discussion comes to mind

https://news.ycombinator.com/item?id=42580659

from memory, the logical explanation is that by connecting to the same wifi the new tracked profile is being used. For example, the grand parent could have been learning Spanish, their profile gets picked up.

Another explanation is observation bias. Spanish ads were shown previously, but were ignored. Now you're on the lookout for them, so they're more noticeable.