• Check if updating to the latest Preact version resolves the issue

Describe the bug
Change #4318 caused that application is not rendered correctly on old user agents. Some of the components blink until they are finally rendered some of them are not rendered at all.

It turned out that isConnected API is not widely available and old user agents are no longer capable of rendering preact app properly.

To Reproduce

One of the user agents I faced that problem is Opera/9.80 (Linux mips; ce-html/1.0) Presto/2.12.407 Version/12.50 HbbTV/1.3.1 (; Humax; fvp4000t; UKTFAE 1.03.54; 1.0.0; wired) ce-html/1.0 FVC/1.0 (Humax; fvp4000t;). isConnected property is undefined.

Expected behavior
Application should be rendered properly.