strange behaviour when using some characters

[Stauricus]

hello
when I try to use some characters, like

Code Select Expand

~ ^ ' ` Codeblocks shows a little square with the signal inside (image attached).

and if I press any key (including print screen) it disappears without doing nothing, and the character is not entered in the editor. I'm unable to create class destructors in C++, for example, since I can't use ~. it used to work well, i don't know what happened...

i searched for it in the forum, but found no answer. any ideas?
thanks in advance!

[BlueHazzard]

Operating system?
Keyboard Layout?
Codeblocks version?

[Stauricus]

sorry, I forgot about that!

Linux 5.8.0-1-amd64
Debian Testing (Bullseye)
Keyboard ABNT2
Codeblocks 20.03

[BlueHazzard]

Spanish Layouts had problems in the past on Mac with the ~ symbol...
Maybe Portuguese layouts have the same problem? Can you try with english layout, if it is still present?

[Miguel Gimenez]

This is related to dead keys, and is a Debian 10 "feature":

https://unix.stackexchange.com/questions/557492/annoying-accent-popup-after-upgrade-from-debian-9-to-10

[Stauricus]

I suspected it could be related to the system, but only happened in CodeBlocks  ???
anyway, I added "XKBVARIANT="nodeadkeys" " to  /etc/default/keyboard, and it is working now. thanks everyone for the help!