The troubleshooting solutions mentioned below should work regardless of the brand of your tablet, e.g. Wacom, Huion, XPPen, Ugee, Parblo, Veikk, Xencelabs, Gaomon, etc.

Determine whether it's a hardware or software problem

Is pen pressure working with other drawing apps?

I recommend you install some of these drawing apps to test for pressure sensitivity first:

• Medibang Paint (free)
• Krita (free)
• Microsoft OneNote (free)
• Wacom Bamboo Paper (freemium)
• Concepts (freemium)

Medibang Paint and Concepts usually have no problems with pressure sensitivity.

If pen pressure sensitivity works with any of 5 apps listed above, it means it's not the hardware fault of your pen tablet or pen display.

1. Enable Force Pressure

Select a brush that works with pressure first, e.g. Brush Pen under the Inks category.

Go to the menu -> View -> Show Context Toolbar

Enable the "Force pressure" setting, then test.

2. Disable Windows Ink

Affinity Photo's default settings requires Windows Ink enabled for pressure sensitivity to work. You can choose to have Affinity Photo not use Windows Ink.

In the settings, under Tablet Input Method, disable Windows Ink and choose High Precision. Restart Affinity Photo.

In the tablet driver's settings, disable Windows Ink.

3. Enable Windows Ink

This solution is the opposite of the earlier fix.

In your drawing tablet's driver, enable Windows Ink under the pen settings. Test.

When Windows Ink is enabled, text cannot be selected with cursor, clicking on icons on the taskbar doesn't do anything, scroll bar's movement is reversed.

This solution is not as good as fix #2 due to Windows Ink behaviour with other tasks.