Select searchbox always visible


I’m using the latest RC (4.1.0-rc.0, full) and Bootstrap version 3.3.5. I need to use this version due to the fact that the form where the selects are use must be accessible. It’s an imperative requirement.

Using it on some selects (multiple and single, the latter with AJAX loading) I’ve what I suppose it’s a bug. The searchbox, that normally appears under the currently active/focused select, is always visible. Moreover, it’s size doesn’t match the one of the select.
Unfortunately I can’t produce a sample to test.


Using a RC version, could it be that this is a problem of this release? Should I wait for the next version (but I’ve a window of time that spans just the next 3 weeks, at maximum)?
Could be also something related to bootstrap and maybe the solution is an option to activate/deactivate?

Thanks for any help.