Using a Mac and Big Sur.
When using the Spreadsheet trying to change information in the cell, the cursor is blinking in the cell, the content of the cell is whitened and upon typing new information it is entered but one cannot see it until I go out of the cell. Very inconvenient even if not a disaster. I do not see it in other applications (e.g., Excel).
Following your questions and then your suggestion:
The vibrating cursor appears in every cell that the cursor enters. Including the Formula Bar or the Bottom Status Bar (e.g., Find). This led me to your suggestion of Big Sur issue. Indeed in an older Mac running El Capitan (10.11) but the same Libre version I never see it. So, if you know how do I stop the cursor vibration on Big Sur, please, tell me. Otherwise, I will hunt it, nonetheless, thanks for your help anyway.
Using LO 7.0.4.2 but the same on earlier 7.0s.
More observations: The problem appears on Apples M1 (Apple silicon) machines as well as regular Intel’s. Appears in any mouse as well as Apple’s Magic-Keyboard-mouse combinations. Persists on wired or blue tooth keyboard/mouse. Another observation, when the cursor vibrates in a cell that contains a formula the corresponding cells that appear in the formula are not highlighted on the spreadsheet. Any changes of the formula are entered but not visible when the cursor is in the cell. Marking/dis-marking any of the cursor controls in Accessibility (System Pref.) does not change this strange behavior.
Is it a Big-Sur Libre compatibility issue?
On the origin of the files: They all came from Excel, mostly from before Microsoft started with subscriptions.
Problem solved: Running LO in “Safe Mode” from its own Help tag solves that cursor issue.