Calc (and Excel) allows formulas to be written and stored multi-line; i.e. in the main spreadsheet view's formulabar, if you unfold the formula bar and use shift+enter, you can use line breaks to nicely format your formula in a way that is understandable. However, the conditional formatting dialog's rules editor sub-dialog, when editing a particular "Formula is" rule, does not allow pasting or writing such multiline formulas. When pasting, only the first line is shown. It should allow writing complex formulas as multiline for clarity.
UX Team -- please take a look at this enhancement. Thanks!
Please share an example. I test with =A1\n + A2\n + A3, copy the formula and paste into the edit field. That results in "A1+A2+A3", ie. the line breaks are removed (as I would expect). Version: 24.8.2.1 (X86_64) / LibreOffice Community Build ID: 480(Build:1) CPU threads: 32; OS: Linux 6.11; UI render: default; VCL: kf6 (cairo+xcb) Locale: de-DE (en_US.UTF-8); UI: en-US 24.8.2-2 Calc: threaded
Cannot confirm the issue, no version information, example is missing.