Independent colums in an independent Sheet shift position when a macro is run

Question

I have a 'seed' column, (Col C), in Sheet1. A button press executes a macro which generates data for 5 subsequent columns after Col C based on info in the seed data. I do a "paste special" (numbers only) of these 5 generated columns into Sheet2. Each column has 40 rows. Rows 15 to 20 are blank cells. After this, when I run any macro on the first sheet, the data in the first column inside Sheet2 moves up!! replacing the spaces in rows 15-20, offsetting my data! The other 4 columns in Sheet2 stay in the right location. I've checked the macro that runs just before the data shifts up, and it has nothing to do with the Col C, or the macro operating on Col C's 'seed data'. The second macro is very similar to the first and pastes data much like the first but is independent (FYI the 'paste special' has 'Don't shift cells' option enabled). I suspect there's some kind of link to 'residual' kind of buffer somewhere that's causing this but I have no idea why/how this is happening?? {LibreOffice Version: 7.6.3.2} Can anyone shed light on this?