It is a known issue that PlayIt Live does not cope well to losing connection with audio devices. Audio devices are initialised once when PlayIt Live starts. If a device is disconnected (or this is a faulty driver) PlayIt Live will not pick it up when it returns (which is why it will work again when PlayIt Live restarts). Please check you have the latest drivers installed for both your sound cards.
I really couldn't get a Soundblaster card to work under the recent versions of Windows 10 at all.
I think you will find it's a Soundblaster driver issue. If you do find one of the newer drivers that actually works I would be quite interested to know.
I've had a bit of a soundcard "habit" and tried a few. At the relatively budget end (where I am) the ESI U6DJ and it's associated driver seems OK
Or UDJ6 even....