Kali Linux live USB stick wifi not working

Hello,

I am running Kali 2017.1 64 bit on a persistent live USB stick and have the following problem:

Every few minutes my internet connection gets lost. While this happens I am still connected to my router and can access its web interface. So my guess is, there could be some trouble with the driver or DNS server configuration. Only my Kali stick is facing this problem, other devices run fine. So the router DNS configuration should be fine.

I had already been looking in the forum for a solution but nothing worked until now.
To solve it I tried the following:
1. edit "/etc/resolv.conf" and changed nameserver from "192.168.0.1" to "8.8.8.8".
2. edit "/etc/NetworkManager/NetworkManager.conf" and changed "managed=false" to "managed=true".

My current workaround is to run "service network-manager restart" but as I have to do it every few minutes it's kind of a mess.

Thanks for any help!