I don't know if my issue is related. Looks like yes, but... I have a server with a domain name xxx.yyy.zzz.local which is located at the office, so I use Cisco AnyConnect to get there. On previous macOS and Xcode, everything worked fine. I was able to open the address in Safari on both macOS and iOS Simulator, and connect to it from an iOS app run by this simulator. Now, after updating to macOS 15.4 and Xcode 16.3, only macOS Safari works. The simulator doesn’t. Safari there just stalls with a white page and loading indicator, and the app output in the console this: {_kCFStreamErrorCodeKey=-72000, NSUnderlyingError=0x600000c74bd0 {Error Domain=kCFErrorDomainCFNetwork Code=-1003 "(null)" UserInfo={ _kCFStreamErrorDomainKey=10, _kCFStreamErrorCodeKey=-72000, _NSURLErrorNWResolutionReportKey=Resolved 0 endpoints in 16ms using unknown from query, _NSURLErrorNWPathKey=satisfied (Path is satisfied), interface: en0[802.11], uses wifi}}, _NSErrorFailingURLKey=https://xxx.yyy.zzz.local/rest/[some path], _kCFStreamErrorDomainKey=10} I tried installing other simulators(18.3, 17.5, 15.2), other Xcode(16.2), macOS(15.5 beta), nothing helps. It looks like the simulator can't find the host ip because mDNS ignores the .local address. Of course, using Charles helps because it redirects all traffic through itself, but that is not a solution. And it doesn't look like a problem with http/3, more like an issue with the simulator DNS resolver, if there is such.