@egika unfortunately, yes. however, as a workaround, the latest version (still in appstore review) adds a restore session feature.
so briefly
you will be able to turn off live.τ for a minute, sync with the suunto app (to update a route or something), and then turn live.τ back on, the app will let you continue your session without interruption.
it’s kinda hacky and not ux friendly solution, but it could works for non frequent things like an route update.