Syncing Issue of Timed Out

I am facing syncing issue between iOS and Mac that always failed syncing by timed out.

It was only happened when connecting to Wi-Fi, but when I switched to Mobile Data or connected to Hotspot from Mac to iOS, it could worked, but it could not worked sometimes.

Mac connecting to Wi-Fi, it sometimes worked, but almost was appearred error, but iOS was often this issue occurred.

Before that I was syncing on previous version of OmniFocus 3, it could sync, but now even OmniFocus 3 is same also always happened error of timed out.

I did not changed any settings of my router.

Does someone having this issue now? Is this my issue or issue of Omni server? does someone knows how to solving the issue?

Thank you