contiguous groups no matter if of columns or lines when saved as .xlsx

this happens long time.

to replicate:

- open new spreadsheet in calc.
- make 2 contiguous groups (F12) like ie.: line 1 to line 10 and line 11 to line 20
- now make another 2 groups like ie.: column A and B, then column C and D
- save it as xlsx format
- close
- open it again
- we'll see just one group in lines and another group in columns 
- it doesn't happen on groups that are inside other groups. for instance, if we initially had made a group let's say of lines 5 and 6, it will remain inside of one big group from lines 1 to 20.

it bugs me because even working for personal use I have to collaborate with people who can't read ods very well.


thank you