An invalid form control with name='...' is not focusable.

Hi,
I have a form with with a custom composite,
the custom composite can be filled up to four times and is shown by condition.
In the composite I have 3 fields that one of them is required.

when the composite is hidden I receive the next code in the console:

An invalid form control with name='additionalworkplaces[items][0][taasuka][select]' is not focusable.

Now, I now it can be handled by adding 'novalidate' attribute to the form tag.
I did that using by checking the ' Disable client-side validation' in form settings.

After doing so I do not see the error in the console,
but when the composite is hidden the form cant be sen't because the required field (that is hidden now) is still required.

How can I act in this situation?