I'm using Minecraft Java 1.18.1
Conjuring v1.0.20+1.18

Lever defected when placed on conjurer but fine when placed on another block.

You are clearly using more mods than just Conjuring, as well as a resource pack. All of this is important information without which it'll be basically impossible for us to track this issue down
Cheers

Are you sure? o_o')

Tested this in a larger pack with the same version and found no issue disabling spawners.
In your image it seems that your lever is floating? It does not look like it is powering the Conjurer at all.
Due to inactivity and the inability to re-produce this issue, I am closing it.