So I went back and looked at my training videos for the past 18 months or so, and as I suspected, my gains stopped right around May of last year. May of last year signified three things in my training:
1) New belt purchased
2) I started form changing
3) I starting getting weird, sharp, dull, and weakened pains in my left arm, right above my elbow.
The new belt helped my squat, a lot.
The new belt prohibited me from pulling conventional that good, so I started sumo, hence the form changing
The pains in my arm didn't affect my deadlift at all, only my bench, as I physically lost strength when it was hurting, like dropping weight on my chest at 80% load.
I had cheap leather belt before, but I wore it out, the prongs wouldn't stay in the holes anymore, hence the inzer 13mm level belt. I could do sumo, but not conventional, I never really knew why, and sort of forgot about it. When reviewing videos before belt, and after belt, I found that I am literally an inch or two higher on the start with new belt opposed to old, hence, less leverage / power. I just can' get into position. That is why I started the grip and rip technique, I could get into position a little better, but it's a crap shoot every-time I grab the bar, sometimes form is good, others I'm above the bar, etc.
My arm pain ended up being my body building bone, ya, wtf I know, but basically, my body had to build more bone for the stress it was receiving, makes sense as I had about a 100lb gain in my squat in a little over 3 months, then pretty stopped for a while so I could work on form / depth as I wasn't consistently hitting depth before.
so, at this time, I feel if I get a smaller belt then I'll be able to get into position better. The alternative is losing weight, which will also get me into position better. However, when I bought the belt, I was 30 pounds lighter, and It affected me then also, so I'm going get another belt for deadlifting, something thin that won't affect my leverage.
I'll try to post back after I get it and let you know how it all goes.
Also, I'm in IT and Quality as my profession, so I do a lot of root cause analysis, this is my root cause analysis as of now