On my '18 Anthem I use the Wiper Technologies WT1000V Vented Wiper Blade - 39".
Compatible with the following:
2009-2009 Coachmen Rv Mirada Class A
2015-2018 Entegra Coach Anthem Class A (OP's coach)
2015-2018 Entegra Coach Aspire Class A
2015-2018 Entegra Coach Cornerstone Class A
2015-2016 Tiffin Motorhomes Allegro Bus Class A
2015-2017 Tiffin Motorhomes Phaeton Class A
They're available from a variety of sources.
Here's one source:
https://www.etrailer.com/Windshield-...BoCMGIQAvD_BwE
The first time I ordered them, I ordered two and the S&H was almost as much as the wiper blades. I now order 4 which pushes the order above above the free S&H limit.
They are a little more expensive than the various options offered above, but these fit my '18 without any modification.
Take care,
Stu