Inability to print through Default print service

Bob Hawkins

I purchased a Samsung Galaxy Tab A 10.5" running Oreo 8.1 recently. I understand "Default print service" was introduced in this version, which is present in Settings>Connections>More connection settings>Printing/PRINT SERVICES. It is switched on and finds my HP Envy 5640 series [144552] printer. Opening, as an example, BBC Food and a recipe, tapping "Print recipe" has no effect, nor does "Print..." appear in the drop down menu.
My mobile 'phone is a first generation Motorola running Lollipop version 5.1. It has HP Print Service Plugin installed by default. Opening the same BBC Food web page, the drop down menu displays "Print...". Tapping that or "Print recipe" opens a new page that is the HP Print Service Plugin, which allows me to alter elements and print successfully.
I know little about printing wirelessly but both HP e-Print and Wi-Fi Direct are on and the printer has no issues, so far as I am aware - I print wirelessly from my Windows PC. I have printed an Inbox email from this tablet successfully, also.
I do not wish to have to download another app such as HP or Samsung Print Service Plugin or Google Cloud Print, when it seems Default print service is present precisely to avoid such a process. I am at a loss, however, to know what next to do.

Bob Hawkins

SOLVED
The culprit is DuckDuckGo browser.  The print facility works in Chrome tapping "Print recipe" in the case of BBC Food, or "Share..." in the overflow three-dot menu followed by tapping the "Print" icon in the "Share via" window that displays.  The "Print" icon is not present when using DuckDuckGo.