Low fluid ?

Hello how are y'all doing, I have a question about the transmission. I have a 904 I drove it around for a good 3 for hours an right before I pulled into my drive way I have to drive down a short tight S shape road after making the second bend the car started shaking an the acceleration wasn't really there.I pulled the dip stick had fluid on it but it had a burnt smell hmm like rubber or plastic, which I smelled once before. would this be a cause of low fluid ? It leaks a little bit an idk how accurate my dipstick is because it missing the top handle, any advice would be appreciated,I will also be changing fluid an filter here soon

Absolutely it could be low fluid.
The smell doesn’t sound very good either.
The shaking was likely clutches slipping.
Did you know that a 904 or 727 either one will spit out fluid if it’s overly full?
Doesn’t hurt it either.
Put another half a quart in it and see how it acts.