Before … as in May this year, your site was running a non responsive layout with Adobe Flash plugins.
That is a meta tag on your site that Google’s report says is not there. It is.
In fact I just audited your site with Lighthouse in Google Devtools which confirms what I see reading the source code of your home page.
Here is info about what that tag does.
Google Crawls billions of pages. Data gets aggregated and consumed in its big data systems, reports are run, emails and notifications are sent out. Sometimes there is a lag between the start and the end of that process. This is one of those cases. Since we can clearly see you aren’t running flash anymore and there is the correct tag in place. Which is why your site renders fine on my Galaxy S8+, my iPhones, and my iPads.
Your site is fine. There are a few issues you can fix according to Lighthouse but I would not sweat it. Hope this helps you understand the issue and puts your mind to rest about the “issue”.