I press 'f' to open the Find pane in a lister. I then start typing into the 'Name' or the 'Text' field. If I type an 'f' into either field, the pane closes again...
Not sure exactly when this broke, but it wasn't doing this in Opus 12.
Hm the hotkey for that should be Ctrl+F, sounds like your Ctrl key got stuck?
It's not my keyboard 
Looking at the hotkey config, which doesn't appear to have changed since Opus12, 'F' is mapped to 'Toolbar:Appearance -> Find Panel', and 'Ctrl+F' is mapped to both 'Toolbar:Menu -> Find Files' and 'Toolbar:ListerMenu -> Find...'.
Both Ctrl+F and F will open the Find panel; 'F' will also close it. Again, this is new for Opus13.
Those are not the standard hotkeys.
Fair enough, but hopefully you'll agree that typing something into a text-field should not be interpreted as a hotkey?
Interestingly, it's the only hotkey I can find which is doing this. I have 'C' mapped to 'Copy', and 'M to 'Move', for example; both of these behave normally in the Find pane's text-fields. So far it's just 'F' which is not.
Ctrl-F is usually set up to toggle the panel.
If it’s assigned as a hotkey, it gets interpreted as one.
(People complained in the past about having to activate another Ui element because the Find edit fields swallowed all hotkeys.)
In Opus12, Ctrl+F toggles the panel as expected. In 13, it opens the panel but does not close it again.
Your hotkeys are nonstandard in that case. Reset to the default toolbars if you want the standard ones, which don’t have those issues.
But as I said, this appears to be the only hotkey I have defined which is behaving like this. All the others are accepted as text-input when the focus is on a text-field.
I've disabled the 'F'. I don't seem to be able to delete it, though - just disable it.
If it was assigned to a toolbar or menu item, edit that (e.g. by double-clicking it in the hotkey list) and remove the hotkey from it.
It's not possible to add option to disable hotkeys when fields are focused please
The hotkey works in the field intentionally. Otherwise you can’t close the Find panel via the hotkey, which is a pain (and something people complained about a long time ago, back when the field didn’t allow the hotkey to work!)
The default hotkey is Ctrl + F, which doesn’t cause a problem. Changing it to just F is a bad idea, not just because of this but because it makes it impossible to type F into the file display to jump to the first file starting with F.
I don't want to close or open search panel.
I have many hotkeys with sequences (eg R then R to rotate image) and today, impossible to search files with 'barrage' in name.