Hey Ryan, welcome to Permies.
The most accurate way to measure the strength of an electric fence is by joule(s). 6000V at 0.25 joule feels quite different from 6000V at 2.0 joules and very different than 6000V at 13.0 joules. I have several fence energizers on my farm, and I've accidentally shocked myself numerous times on all of them. 0.5 joule is kinda unpleasant on a finger tip, and 2.0 joules hurts, and 13 joules almost knocked me to the ground - I felt it in my chest even though it was the back of my hand that made contact with the fence.
Can you look at your fence energizer and let us know how many joules it produces?
Also, fence "hotness" has several variables in the equation, and when a fence isn't quite working right the most common thing at fault is a poor ground with inadequate ground rod(s). Also, dry soil will reduce an electric fences effectiveness. Another thing to consider is hooves don't conduct electricity as well as padded paw feet. What may keep a fox away may not be
enough to have an impact on a pig, goat or cow as examples because of their feet.