Firewall user-defined applications list is broken with more than one application defined

I have gigapower internet with router model 5268AC FXN.

I'm talking about the router configuration page Settings -> Firewall -> Applications, Pinholes and DMZ.

I have created 2 user-defined applications via the link "Add a new user-defined application". When I click the link "Edit or delete user-defined application", that page comes up with an EMPTY list. When I had only one application, the application appeared in the list and I was able to edit or delete it. But, as soon as I added the second application, the list shows empty.

Attached are 2 screenshots showing clearly that I have 2 user-defined applications defined, and then the "Edit or delete user-defined application" screen with the empty list.

So, can someone confirm that this is a bug in the router management software and get it fixed? Please note that the applications added work correctly (I can add them to devices and the ports opened just fine, etc.), it's just that if I want to edit or delete them, I cannot do so.