Some array formulas (mode.mult, frequency) are not working in Onlyoffice. Instead of outputting different results, they repeat the first one.
Please try to reproduce the situation with Ctrl+Shift+Enter hit on selected cells. We described it here: Insert array formulas - ONLYOFFICE
As far as I understand, this is what you are looking for.
I selected array where I want to display results, typed
=mode.mult(B2:B6) and hit ctrl+shift+enter. It repeats the first mode instead of showing all of them.
In microsoft office (online) ctrl+shift+enter does nothing but hitting enter displays all modes and leaves unused cell blank.
We rechecked the issue and we added a bug to internal tracklist (internal number - 56846).
We have started working on it.