Loose bales with new tractor

I didn't figure this out until it was time to move the bales.  Baler in question is a Vermeer Rebel 5420 kicking out little 4x5 bales.  I've run this baler for 5 years with either a 70 pto hp open station tractor (sold) or an 85 pto hp cab tractor.  The new tractor (cab) is smaller, but has all the bells and whistles.  The powershuttle is great for stopping and starting without having to use the clutch.  PTO HP is listed at 62.  Vermeer says you need 50hp to run the baler.  

 

Flat land, same fields I've always baled.  Same windrows, and baled at close to the same speed.  (5.5 mph)  Baler didn't have any issue picking up the hay at that speed, and the engine never slowed down like it was under a load or anything.  The new tractor does have the electric push / pull PTO engagement lever, where all my older ones have had the manual throw the lever forward to engage the PTO.

 

Bales that were done on the bigger tractor 8 weeks ago were tight like always.  These bales were so loose it was obvious because they sagged down close to level when you tilted the front end loader back.  You can easily reach your hand in and grab hay out of the bales with the new ones.  The 8 week old bales you have to fight to dig into it and get some out.  

 

I understand how to adjust bale density, but I'm thinking there's something going on with the new tractor that's causing this.  I wish I would have thought to check bale density when baling instead of just using the eyeball test.  Hydraulic pressure  and flow rating of the new tractor is actually better than the older ones.  I don't have a hydraulic gauge on the baler, but will probably add one just to watch.  I'm looking for other input or advice on what to check or how to test.  My first thought was maybe the PTO clutch was slipping, but since there were no issues picking up the hay even in the thicker parts, I'm leaning against that.  

 

I'll probably try running it a bit higher than 540 rpm next time and see if that helps.  If not, I'll switch back to the old tractor for a bit to confirm it's a tractor issue and not a baler issue.  I don't want to adjust the baler to compensate for a tractor problem if that's what it is.

Loose bales with new tractor