Connect your fences and walls with a decorative chain!
Connect your fences/walls/iron bars with a decorative chain!
Use the normal vanilla chain item on fences or walls.
These chains have collision and can be broken when attacking it with a shear.
Sneak on fences if you want to place them normally.
If there are invisible collisions for some reason, hold a shear while having entity hitboxes on (F3+B) to see the collisions and then attack them to remove them.
For images, check the Modrinth or Curseforge page!
See the wiki.
There is a forge port however I do not maintain it.
https://www.curseforge.com/minecraft/mc-mods/connectible-chains-forge