Same problem here. Brand new Ipad Pro 2020 11inch (2 months old). I updated to Ipad os 14.3 directly when it came out. Since a few days I have the battery life ever (currently on Ipad Os 14.3). It all started with Ipad OS 14. On Ipad OS 13 it was great and I got an amazing battery life. Charged the Ipad yesterday up to 100 % and shut it of entirely. Turned it on today and it just had 78 percent left. A few days I still had 10 percent left and it just turned off. I get with super low brightness 4 hours screen on time. I can watch the battery percentage dropping. My girldfriend has the exact same device, exacatly the same apps and Ipad OS 14.3 installed all services etc. are turned on and no problems at all. At the moment everything is turned off. No syncing, no location services. It’s such a desaster and I am super frustated for a device with such a high price tag.