Sample 1
This is usually ugly copy protection. I have it on a Young Indiana Jones Chronicles tape, and a The Tick cartoon tape, and both are in my TBC testing stack for that reason. The Tick can be reduced with JVC TBC off, ES15 in use, and is still touchy with external TBCs, doesn't like frame syncing. The signal is screwed.
But it can also be a natural error, usually on re-copied tapes. The error was on my homemade VHS EP set of Voltron, and is an image that I used for the main site JVC TBC guide that shows how TBC can sometimes hurt an image. Rare, but happens, so wanted others to always try turning it off. But the ES15 almost always fixed natural errors.
Sample 2
The upper signal is damaged, and either presents as tearing, or correct with potentially missing lines, hence the image jitter.
Anyway...
The software fix is to crop tearing, and stablize jitter with my Avisynth stabmod()*
* stab() with tweaks for VHS source.
Keep playing musical hardware, see if a combo works. Another reason to have lots of VCRs, TBCs, capture cards.
Sometimes settings of the hardware.
Welcome to video, welcome to my world. Are you having fun yet?