What I did: Just Input texts.
What happened: Same character is entered twice. (ex. II LLove YYou.)
What I expected:
Things that might be helpful to know (Agenda version, OS and model, etc): Agenda 4.1, iOS 12.1.2, iPhone Xs.
We should have fixed this in the most recent version (4.1). Have you got that most recent download from yesterday?
If so, are you using a special keyboard or entry method?
I have the same problem of text duplication when using Agenda on my iPad. It occurs when I am using Chinese (Simplified) to type in a note. For example if I type “你好”， it will appear as 你好你好. It is rather annoying because I have to go back and delete the repeating words. It does not happen when I am using the English input method. I hope that this can be resolved soon with the next update. Thanks!
Yes, I used a custom keaboard.
I tested with a genuine keaboard, that didn’t happen.
I hope that this can be resolved soon, too. Thanks! 
same problem with chinese character
Unfortunately, trying to fix the problem with the Chinese keypad entry has messed everything up for other asian keyboard types. We will investigate this as soon as possible and release a fix. Sorry for the trouble.
No problem and thank you for the promptness!
We just released version 4.1.1 that should fix this issue, it should become available in the App Store within the next few hours. Thanks for reporting the issue to us and apologies for the inconvenience it has caused.