is there a chance that you could post where you are seeing these shows? or start a thread about it.
I bought a roku and have not been able to find any decent content for free or low cost.
All of these are available on Roku.
Tubi is free.
Youtube has a lot of older movies and TV shows. The image quality varies and you have to search for them. I find it helpful to search for actors you are interested. Youtube is also very good for documentaries.
The various Filmrise specialty channels.
Classic movie vault.
My Retro Flix.
Classic TV & Movies.
Some of the quality on these channels is not very good.
There are many free streaming sites on the web. They are pretty easy to find. But I would make sure you have good ad and popup blockers installed and watch what you click on.
Depends on what you are looking for. If you have Amazon Prime, you can stream a lot of stuff "free". Of course, it is not really free because you paid for the Prime membership, but there is no additional fee to stream Prime content.
You can also build a digital library of movies and TV seasons. If you buy a new Blu-ray, it often comes with a free digital code which you can add to your library. You can also find message boards where people sell those digital codes for a few bucks apiece.
I forgot to mention that VUDU is also available on Roku. It has free and paid content and is plainly marked which is which.