Macros disappear

Hi,
I was helping my daughter by making macro's on her PC. She's working at home with Office 365 from her boss.
I made the first macro and the worksheet was presented by an app (no clue what that app does). The macro's have to be for her working on any workbook that she opens, general.
Storing this first macro was only possible with the worksheet or on her personal storage. When I made the second macro on a different worksheet, storage was different; it was (what I was used to see) on the workbook or in general.
The first macro didn't show up anymore. It seems that the two workbooks are on different Office platforms or configurations. Anyone ever experienced this and knows what you can do to avoid this?