As this issue appears for you in the latest beta, the most likely reason is the change to allowing on KEYDOWN in all windows.
Can you try this in beta 7.63.416:
1. Create a custom @window with an editbox: /window -e @test
2. Type your accented key in the @test window. Do you see the issue?
3. Now type your accented key in the status window. Do you see the issue?
In the custom window the accentuation failed in the first letter that I added accentuation. Then I went to the status window and the accent did not fail.
This test I did in the last beta version.