Venue 11 Pro -> Pen not working after upgrading to Windows 10 2004

After installing the most recent version of Windows 10 (2004 or 10 May 2020) the pen (model PR77S) stopped working on my Venue 11 Pro 5130.

I contacted Dell support and I was even redirected to 2nd level (premium) support, but even that didn't help. They were really disappointing. At one point they even denied the PR77S to be one of their products.

I understand that that pen wasn't one of their best things, but denying its existence seems too much. After all, in the last few year I bought at least 3 of them, even on their online shop.

And yes, I replaced the battery with a new one...

Anyone who can help?