The IncrementalSearch appears to be broken in this version (not sure about older Nightlies). The text control sometimes does not accept input focus, so when you try to type something there, the text goes into the man editor instead.
It does not happen immediately, but this seems to be repeatable:
1. Start C:B and open an existing Workspace with some source files open
2. Click in the IncrementalSearch text control - no problem - input fokus ok
3. Click somewhere in the open source file
4. Click in the IncrementalSearch text control - it does not accept input focus
5. Type some text to search ... it appears in your source file instead of the IncrementalSearch text control
Platform Win10
This is a significant bug...