I installed latest iOS 18 beta and the same exact issue described above still exists. Everything works as expected on iOS versions older than iOS 17.4.x

From our tests on iOS 18 beta, the issue is not fully resolved (so in a sense not solved at all). While now the workers keep working even after the 30 seconds of use pass, if the user is exiting Safari or the device is locked and unlocked, from that point the listener in background.js does not continue to receive messages (from native or web js). If Safari is terminated and relaunched, everything starts working again (until user again exists/returns from/to Safari).