kCFErrorDomainCFNetwork error 310

[nicovon]

hello, in the network of the institute, on all windows pc we can connect to spotify both in client and browser mode, while on a mac computer there is the error code offline on the desktop client while on the safari browser: safari can not connect to the proxy server kCFErrorDomainCFNetwork error 310 now, in the institute is true we have a web proxy (squid) and I have already set it in the network settings on automatic configuration and in addition on some devices I have to add the proxy url .. all other sites work, only spotify no and only on this mac (maybe also on the other mac) .. what will it be?