Hi LaynLan,
Thank you for your answer! I have also done further research and have come across further inconsistencies. The device was reset to factory settings in the Apple store. Despite this, the error still persists. I noticed that I had two identical PDF files with two different file sizes in the cloud. I emptied the cloud and it is no longer connected to the device.
I have analysed the analytics data and there seem to be hardware and software issues on the device. For example, a CPU usage of 98% percent and low memory. This doesn't seem to make much sense immediately after a factory reset. Someone had tried to hack the iCloud. However, this attempt had failed. A support employee noticed that MDM profiles had been created on my device. He helped me to remove them. Before the removal, error messages were suppressed and I could no longer click on some security settings. My Norton antivirus is still causing problems. My Google and smartphone accounts were also attacked. I changed all passwords and reinstalled everything.
Answering your question: I can't really see the icons. Question marks are displayed instead. I have disabled the autofill option. How did you scan the iCloud? Have you enabled the option „Share iPad analysis“? If so, the analysis is sent to the Apple developers anonymously. This way, they see what‘s going on on your system.
Have a great day!