I am opening a macro-enabled Excel template in FYI. This is not allowing AutoSave to be turned on. The information under the AutoSave message says that it is an older file format and as it is a macro-enabled worksheet, I cannot convert it to a newer version.
It appears the issue is being caused by the compatibility check being run when saving the document.
Disable the compatibility check and this should resolve the issue. You can choose to deselect the option to check compatibility when saving the document. To disable this for Excel entirely refer to this Microsoft article https://support.microsoft.com/en-gb/office/turn-off-compatibility-report-eb634b94-f173-4c0a-97e7-63883fc1b038.
As this is a Microsoft feature, if please also check with your IT consultants.