Guest User in my app even if i have user sign in restriction

[SSC]

HI…
i am on appsheet core plan…

In My app,

i can see guest_-956001730 as my user…

i have strictly enabled require user sign in from my app right from the very start and have permitted only some users email in my app… who is this guest_-956001730 user and how is he able to access my app???

i have seen unique app interactions of this guest_-956001730 user in last 3 days …

30/4/2021 - 6 Interactions

18/5/2021 - 12 inetarctions

19/5/2021 - 5 interactions

20/5/2021 - 5 interactions.

There is no activity of guest user in audit log or performance analyser… So how are there any interactions?

I wrote to support@appsheet.com
But they said the guest user might be somebody that has the link and/or was revoked from accessing your app.
Even if somebody has link… how can there be 12 interactions??
Is he able to see my data? Also Its clearly written about guest user in app that:

What is a “guest” user?

You may see users on this list identified as “guest” users. A guest user is recorded whenever your app is used and the person using it is not signed in. Since we do not have signin information, instead we rely on identifying the device/browser being used. As a result, if Sarah uses the app once from a phone, once from another tablet, and once from her desktop, AppSheet would count this as three guest users. If you are on a per-user subscription plan (AppSheet Starter, AppSheet Core), please make sure all your deployed apps require user authentication (i.e. force users to sign in). Please be aware that the information shown in this chart is from the last 30 days of usage, so even if you make a change today, it may take up to thirty days for old guest user information to stop showing.

So how can someone use my app if he is not even signed in??? Or how can appsheet count the app as used if he is not signed in?? Or Is this a security flaw that guest user can access appsheet inspite user restriction?

Kindly elaborate if someone is getting any idea. i am not satisfied with whatever appsheet support said to me. Because this raises a security concern with every organisation using appsheet if they are getting random guest users…