Copy and Paste Formula without copying tab name

I have a spreadsheet with multiple tabs (one for each month).
Sometimes I need to copy a row including formula from one tab to another, however when I do this the formula automatically adds the sheet name in which then means my formula in the second tab is referring to the wrong data.
I have never manually added the sheet name in when writing the formula, is there a way to stop it happening?

Thank you

(The label on the glass and the jam in the glass are different things. So are the tab showing the sheet’s name and the sheet itself.)

What you describe is not the regualr behaviour of Clac.
What’s your LibreOffice version? I have a faint impression of memorizing an old version which had a bug to the described effect.
Do your formulas you want to copy from the other sheet already contain a sheet part in their references? If so, has it prefixed a $-sign?

I think we are on number
There is no sheet reference in formula, a basic example is when I paste the formula it looks like this =IF($January.F3="","",$January.F3-$January.G3-$January.H3) I try and manually remove the $January. but it automatically adds it back in.
Thank you

Well. The version(s) having a related bug was(were) early in the 5.x series. See tdf#96591 e.g. Seems you are afflicted.
Best update to V5.4.7, the most matured version of the 5.x series, or to V6.0.7 probably.
(You may first test if a corrupted user profile was the villain in your specific case.)