Can't invite users to share my Home

I believe there is but I’m not really sure. I haven’t upgraded every device yet, you’re supposed to update all devices first. Not done my Mac and I did HomePods before the others. Also once you do, the iPad is no longer a Hub and mine are still. I’m obviously not on the new architecture. I’m just not interested in it at this point. I have another iPad stuck at ipadOS 15 so that’s a problem. All devices must be running the latest software.

It says this:

Upgrade in the Home app

Follow these steps to upgrade any homes you set up to the new Home architecture. All of the homes that you own are upgraded at the same time.

1. Open the Home app on your iPhone or iPad running the latest version of iOS or iPadOS, or Mac running the latest version of macOS.
2. Tap or click the More button .
3. Select Home Settings . If you own multiple homes, choose one, then select Home Settings . 
4. Select Software Update.
5. Tap or click Learn More under Home Upgrade Available, then follow the prompts to upgrade.
6. 

Upgrade to the new Home architecture - Apple Support

This continues to be an issue for some users. All you can do is wait for a software update to eventually fix it. Some have found workarounds: Apple Home Invites Not Being Received Best you just wait imo, there will be other changes with HomeKit on a future update. You can also submit feedback: Feedback - Home App - Apple

well, now I guess this issue is not "china only".

I live in china, and it happened too. so when I try million times, I finally know there is no fix way.

BUT! actually you can share your APPLE ID to him, like me and my wife.

I heard that happened like several years, and pretty sure APPLE won't admit it.

How do you mean, "upgraded my home to new architecture."? Is there a step for doing this beyond upgrading all devices to the latest OS?

Thx.

but it not happened now. if m not wrong, first I heard that is IOS 15.