Pressure for brush size ignored when holding shift for straight lines (dot2dot)

I too have the same problem but with an XP-Pen tablet (Deco LW model). I have found out some things that might be helpful in troubleshooting the problem but I don't know where to go from here.

First here is everything I have tested that didn't work:

Resetting tools

Resetting Photoshop Preferences

Using different versions of Photoshop (tried 3 different ones).

Using different versions of my tablet driver (again 3 different drivers) and doing clean installs each time

Updating Photoshop, my graphics card driver and the tablet driver to the newest versions

Plugging my tablet into a different USB port via cable

Using the wireless receiver for my tablet and plugging it into different USB ports

Using wintab driver (with PSUserConfig.txt file) and unchecking windows ink in the tablet application

Using the windows ink setting on my tablet (without PSUserConfig.txt file)

Disabling pen and touch settings in Windows

It is important to note that this wasn't a problem with my older Wacom Intuos 5 tablet and I don't remember it being a problem a few months ago with my XP-Pen Deco LW tablet (I have reverted back to the settings I had a few months ago with the version of Photoshop and the tablet driver I had a few months ago and it didn't fix the issue).

Here is what I have observed from my testing:

Using the Hard Round Pressure Size brush and default tablet settings (using wintab in photoshop), when I press hard on the tablet only a tiny little dot appears. It isn't until I move the pen (still pressed down on the tablet) that Photoshop registers the hard pressure and gives me a larger stroke. So it seems to me that Photoshop is taking the initial input of when the nib touches the tablet to determine the size of the stroke/dot. This is fine when I am drawing regularly but when I shift click it doesn't take into account the pressure in which I press at and only gives the initial reading of the pressure (which most of the time is going to be really low because when the nib bearly touches the tablet it isn't at a high pressure). Perhaps this is an issue which how often the tablet or Photoshop updates the pressure reading, since there are a few times where the stroke comes out big (but this seems random). This would never happen with my wacom but I seen past threads about this with wacom users.

Attached is an example of how the shift + click operation is behaving.The big dots at the end of the stroke come out because I move the pen just ever so slightly after pressing hard.

Going with the shift click function for years in industrial design and illustration, I'm quite used to it (no problems with the precision). And unfortunately it is so ingrained in my sketching workflow, that switching to mouse while sketching is not really an option. Especially since it worked on both an older Wacom Cintiq, and a Mobile Studio pro. (It had its own kinks there, such as the occasional dot at the beginning of the line, but that didnt bother me too much - it did what it was supposed to do)

Any ideas if it is likely a huion driver issue, a PS issue, something in between colliding with a windows function, or simply a brush settings problem? (I feel like i can rule out the last one, tried it with different brushes, different settings - same result everytime i shift click - thin line, pressure is being ignored)