https://snippet.webix.com/0a1iarc3
In Chrome after typing the input-field will lose focus.
In Firefox the input will disappear
The problem occurs if the validate method is manually called while an element is focused too
Hello @Jendrik, the current behaviour on Chrome is within the expectaions, but the issues with the text input being emptied that are present on Firefox/IE are unfortunately a bug. We are currently looking into the issue and will try to provide a fix for this in the future, the focus loss behaviour might change as well, but no promises here.
To circumvent this for the time being you could validate your data after you’ve finished an input.
https://snippet.webix.com/zz34xn9w
Also 
validateEvent:‘key’ works strange with pattern after marking field invalid