Just one sheet refuses to adher to conditional formatting

I have 5 sheets with the same conditional formatting (honestly, I don’t understand if they’re really shared or sheet specific, the manage pop-up doesn’t really say).

However, on sheet 6 (which is basically a clone of the others), the conditional formatting does not work.

I see no difference between the sheets. When I try to manage the conditional formatting with that sheet selected, it looks exactly the same as other sheets.

If I clear direct formatting, the conditional formatting does not appear.

The only thing I can see is that on the problematic sheet 6 I can’t right-click on a cell to manage the direct formatting like on the other sheets. What else can I look for?

Your conditional formatting is always looking at sheet Räkning1, if the data there is different to that on sheet 6 then you should not expect to get sensible results from the conditional formatting as part of it will be looking at a different sheet.
Do you need to specify the sheet? If not delete the sheet reference.
See the problem here where the second sheet is looking at the data from the first sheet, not the second sheet?
ConditionalRefSheet1CopiedToDifferentSheet.ods (17.7 KB)

Thanks, but that’s not the issue I’m having. The issue is with the range “T3:T18;A3:A17” which works on all sheets except the problematic one.

Maybe you need to define the range for Sheet6, so in the range enter Sheet6.T3:T18;A3:A18 and OK. It seems to nudge the system into looking at the current sheet although the sheet name is not saved.
See also Erratic Conditional Formatting problem and tdf#126327

Could it be a protected sheet?