Hey everyone, we’re aware of the bug and the team’s on it. The regression is noted too.
For now, there’s a working workaround: before typing the commit message, open the Command Palette with Cmd+Shift+P or Ctrl+Shift+P. You can close it right away. After that, the lag goes away until the next Cursor restart.
More details and discussion of the same bug are here: Commit message box lagging - #4 by celestialorb.
We’ll update this thread once there’s a fix.