Calc no longer shows the option to save as Excel 2007-365, my user specifically needs this option.
Please paste here the information on Menu/Help/About LibreOffice (There is an icon to copy)
This means that you now somehow started using an older version, than were using before. The rename from “2007–2019” into “2007–365” was done in commit 77ae0abe21f672cf4b7d2e069f1d40d20edc49a7 in 2019.
And this was just a rename of the entry in the combobox. The file type is the same.