You may have solved it by now since it’s 4 months later, but for the benefit of anyone else who has the same issue, all I needed to do was allow UDP port 123 (NTP) outbound to pool.ntp.org.
Once I opened that port everything started working properly in HA, but the iOS app still had a few issues… not surprising as it seems mostly cloud based. Not an issue for me, as I only use it to initialise my Tapo plugs.