Checkbox Shape Changes

[MohammadKh5E93]

Hello

I have a problem in pdf interactive checkboxes which turns from a circle to square automatically after exporting the design into pdf (interactive) 

you will understand my problem properly by watching the video I have uploaded.

Note: I am using indesign 2021 version

Thank you...

[Bill Silbert]

It looks to me like instead of designating the box as a checkbox you actually made it into a Radio Button. Check this in InDesign by selecting the square you want to make into a check box and then looking in the "Type:" pull-down menu that is at the top of the Buttons and Forms Panel.