do you have search console added to these sites...
if so it may be worth going to security and manual action>>security and seeing if there are any actions against your sites...
apparently goolge blocklist around 10,000 sites a day...
read more about it here
https://sucuri.net/guides/how-to-remove-google-blocklist-warning/

I make sure my domain name

SiteSSL (HTTPS)

is switched to ON clicking details on the domain in question in the site manager

https://my.wealthyaffiliate.com/websites

You may also try to empty the browser cache, refresh and try again. Try the URL in a different browser or mobile device.

You can also empty the server's cache.
Websites > Site Manager > Details > Sitespeed > Empty site cache

https://www.wikihow.com/Clear-Your-Browser's-Cache

See if there is any change, or else again, reach out to site support

You need to click the fifth button option in PM messages. Or help tab top menu and site support.

Report Incorrect Phishing Warning

https://safebrowsing.google.com/safebrowsing/report_error/?hl=en

Hi Kolas that sounds it could be an SSL issue. I would contact site support and share all the websites that are getting this warning. Here is a link to site support:

https://my.wealthyaffiliate.com/vitaliyg/messages/sitesupport