Honestly, I have always had some form of this problem with all my iPad Pro models. It seems to come and go based on what iPadOS release we're on, and I gave up trying to figure it out long ago, after spending hours and hours of my free time troubleshooting and driving back and forth to the Apple Store. Granted, your problem doesn't sound too severe, but keep one thing in mind: 100% to 94% is a lot more than it sounds like. It always takes a lot longer for your iPad battery to go from 100% to 99% than it does to go from 99% to 98%. There's some buffer present when you're charged up to 100%.
I can give you some advice based on my own extensive testing that may help you figure out if there really is a problem and how to possibly solve it:
1) Take a look at your battery percentage tonight and log that number and time of day it was at that number. DO NOT start at 100% charge. It's easier to detect excessive drain if you start less than 100%.
2) Let the iPad sit for the night not in use.
3) In the morning, notate the battery percentage and time again.
4) I'd say if you see anywhere from 5-10% drain overnight after the above test, you're in a pretty normal range. If you are seeing more than that, you need to look at the battery settings and see if something is running in the background overnight to wake up the iPad and make it do things when you're not using it.
5) If, like me, you see no apps draining the battery overnight excessively, the next night try turning wifi off and letting the iPad sit overnight again. You'll most likely find that it doesn't drain at all, or drains very little.
Again, the only fix I ever found was turning off wifi. After a couple of iPadOS dot releases, the problem would stop and I could leave it on again, and then something else would break it. I've been through this about 3 different times with 3 different iPad Pros. It's maddening.
