If you're using these:
It's likely your colleagues are not on the same 365 update channel as you.
Checkboxes in Excel (microsoft.com)
Availability:
Don’t have it yet? It’s probably us, not you. Features are released over time to ensure everything is working smoothly.
Windows and Mac Desktop: Fully rolled out to users on Current Channel [Updated on July 31, 2024]
On Web and Mobile (iPad, iOS & Android): Partially rolled out to production users [Updated on July 31, 2024]