Is this recent?
I have a wacom Ctl490dw, it works perfectly, however today it presented some errors, when I checked the driver it was outdated.
Open the Wakon Desktop Center and see if it's all right.
This is the first time I've tried to use Photoshop with my pen in a few weeks. My computer had to be replaced, and it took me 10 days to get everything reinstalled, updated, etc. (not 10 days working straight, just as I had time and energy to do all that). For me it is recent, but it had been probably 20 days ago that I used Photoshop with my pen on my previous computer. My drivers are up to date, and everything else works fine. If I turn off Windows Ink, it works, but then I lose pressure sensitivity. I have had a constant battle getting my Intuos Pro to work well with Photoshop; every time I get it working, Windows updates and it breaks, Photoshop updates and it breaks, or, for the first time, my computer breaks and I'm set back hours of setting everything up. There's never any actual help; I usually end up messing around with a hundred different options until it works well enough. This is the first time I've posted in Adobe about these kinds of troubles because, frankly, very little browsing of the help section or forums ever helps me. Sometimes I get lucky on youtube, and sometimes Reddit, but so far, no help in Adobe. I came here because I've been striking out for hours, and no amount of tinkering is getting me up and running.
The command to resize the brush tip is hold down Ctrl + Alt as you right-click and drag the pen right or left, then release all to save and exit. Move the pen up or down to change the Opacity. I have the 2016 Intuos Pen & Touch tablet, and it works very well on that.
I share your frustration with Wacom. I'm preparing to post about my ExpressKeys and Radial Menu not working in Photoshop for I can't remember how long! I could be wrong, but I believe it is Wacom's fault for not updating its drivers to work in properly Photoshop.