Have you tried using the action button with a microflow and close page activity?
i even had that issue. if you observe some times close page buutons gives trouble. not only close buttons i used to get trouble with default created edit page buttons. i solved this issues by removeing close button and place action button and create a microflow action for that, in the microflow just add activity and double click on it and choose close page option problem solved.
not only close page button save and view button actions also can possible to create using microflow. make a habit playing with microflow.
there are two things you should NOT confuse.....
The SAVE and CANCEL button options for a Dataview WILL close the current form. If your Dataview is Read-Only then you should use the CLOSE button, which obviously also closes the form,
Then there is the "is Close button" property on a Dataview. Here is where most confusion comes from:
this property does NOT define the button that CLOSES the form, but rather the ACTION that is taken when a form is exited using the X (window closing option). So if you set that property to "SAFE" then, should a user X-it the form, your data will still be saved....
I have never noticed other behavior in any of my Apps, but you might want to migrate to the most current Modeler version, just to make sure.
Also, as stated above, there is always the option to go with an ACTION-button and define a microflow which will close.