This is a known issue of skype app. Just do a search on google and you see that you are not the only one. i heard there is a moddem skype version that doesnt have this issue. Just give a try.
Inviato dal mio Nexus 4 utilizzando Tapatalk
Which version of Skype you're referring to?
Sent from my Nexus 4 using XDA Premium 4 mobile app