Manual text and backtick (`) Gemini answers use the same overlay. A new Gemini answer replaces the current text but keeps your color, size, and position.
In Move / Resize Mode, drag anywhere inside the overlay to move it. Drag its bottom-right corner to resize it. Click Lock Overlay when finished so mouse clicks pass through it again.
Keyboard shortcut: press F8 on the overlay PC to toggle the overlay between shown and hidden.