FT900 VTFT limit?

[ACPUK]

I have been working on a project for over a year now.
I am using the mikromedia HMI FT900.
Up to 10 screens now and one of them I need a keyboard to allow user name entry. However, as soon as I go beyond 21 objects, buttons in this case, the screen brakes up.
i.e I can get from Q to Z, ok but as soon as I add the Z key it dies.
It this is limit?

The more I add the worse the screen brakes up.

Project is too big to upload and contains confidential code.
I will test on another simple project.

thanks

[ACPUK]

I have exported the screen into a standalone project, which I attach.
this has all the kays enabled and the screen is very broken.