Stash filters will not scroll on PC

Stompya

When I try to use filters on my ISO-8 stash, the pop-out box on the side of the screen will not scroll.

Playing on PC
Inventory > Stash (overflow) click the ISO-8 tab
Click the filter icon on bottom right
then click 'filter'
You can see the CLASS options (Basic and the 6 colours) but the TIER options will not scroll to show more than Tier 1 to 3.

Stompya

In troubleshooting I have tried changing the resolution and I have tried in fullscreen and windowed mode with no change.