An environment: - Safari 14.1.1 (16611.2.7.1.4) on macOS 11.4 (20F71); - g8 template with root d72db85933f91a4d9f012ee2d8c643c36c4a40ac. A step to reproduce: - create a new project by `sbt new UdashFramework/udash.g8`; - start it by `sbt compile compileStatics run`; - open safari and go to a page; - log in; - refresh a page; - log in one more time; - see that number of connected users is `2`. The video: https://user-images.githubusercontent.com/37775/127490487-5d3cc76f-5457-42f4-b489-33ae97cb3644.mov The issue doesn't appear on Firefox, but it appears on Safari Technology Preview 127 (Safari 15.0, WebKit 16612.1.18.11.3).