Hi @Noam_Weinbach, this is a known bug in v2020.2.4 (hopefully fixed in 2020.2.5!).
The current work around is to put this line in End Routine of a code component:
psychoJS.experiment.addData('myTextBox_txt', myTextBox._pixi.text);
where ‘myTextBox_txt’ is the name you want for the textbox output variable, and ‘myTextBox’ is the name of your textBox.