It is not. The entire assembly shown in the image below is the Power Distribution Center, which includes the block and fuse box. The PDB is called out as "18 & 19" on the image. I am not 100% sure but I think the block is located below the fuse box. I found this image on a mopar parts site.
I had this same problem with my Wrangler JLU. The dealership "tried" to fix it 3 different times by replacing the aux battery to no effect. After much research, I found a post on the wranglerjl forums where someone mentioned the Power Distribution Block on there's was loose. Had the dealership...
If you hate the ESS as much as I do, give the auto start/stop eliminator a try. It was designed using my 2018 JLU and works with the Gladiator as well. All it does it sends a code to the computer of the last setting that ESS had while the vehicle was running. I have it set to turn off the ESS...