Sometimes, without expecting it, a pink border appears around a cell or several cells in Calc and causes the arrow keys to always jump the cell selection back to that area no matter where I click with the mouse. It seems to grow arbitrarily unless I quit and reopen. Track changes is not on and there’s no conditional formatting. Please see this video to observe the behavior.
Edit: it seems to grow when I tab ⇥ or return 
to finish editing any non pinkified cell. Editing the pink region cells doesn’t cause it to grow. It seems to shrink when I ⌘⇥ to switch applications and back. Or at least, it will adjust its size based on the current cell selection. It also adjusts the size of the bordered range whenever I scroll.
Version: 25.8.0.4 (AARCH64)
Build ID: 48f00303701489684e67c38c28aff00cd5929e67
CPU threads: 24; OS: macOS 13.7.5; UI render: Skia/Metal; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded