This conversation has been merged. Please reference the main conversation: Photoshop CC 2018: Selected a brush but instead it changed to a tool
Most brushes are locked to a particular tool.
This seems to have been a deliberate choice by the dev team, and I get why. Each tool has its own unique settings, and by making a brush tool-specific, those unique settings can be saved along with the brush. That's a great feature, but the problem is that there's no way to use these full-featured brushes with any other tools.
So now, if I want to test out different erasers, I can only use the brushes saved without tool presets (General Brushes and Legacy Brushes) and the Kyle Webster brushes saved as erasers (of which there are very few).
Please, Photoshop devs, add an easy-to-access checkbox that allows the user to either use brushes' tool presets or apply the brush to the selected tool. For instance, "Use Selected Tool" or "Use Tool Preset."