Created attachment 177639 [details] Screencast If you type in a cell "- preserve the meaning of columns" and press Enter, Calc will forcibly autocorrect "columns" to "COLUMNS()", and Undo won't work. This seems like a corner case, but the way I found this bug was that I was entering a list of items one per cell, starting with "-".
Reproduced on Linux and Windows. Oldest tested was oldest of Linux 6.3 bibisect repository. Arch Linux 64-bit Version: 7.4.0.0.alpha0+ / LibreOffice Community Build ID: a86669f4301541b446cab2e4fbbe1d86ba8a8a38 CPU threads: 8; OS: Linux 5.16; UI render: default; VCL: kf5 (cairo+xcb) Locale: fi-FI (fi_FI.UTF-8); UI: en-US Calc: threaded Built on 20 January 2022