Aside from the "banding" issue, which look very similar to compression artifact, I can't spot any oddity with these images to say they are AI generated 😳
SD always has certain characteristics that make it obvious, like odd fingers, odd text, odd skin, odd patterns.
check out comfyui if you can run it locally
Some of the open source video generation model or technique are WanX, LTX, framepack and animateDiff
Use controlnet for controlling pose and structure
there are plenty of tutorials online. But getting a good quality generation may take time and require some technique