Curtain head area conditions are specified in TBDY 2018 article 7.6.2.1 and Figure 7.11. By default in the program, header regions are created according to these conditions. The user can change the length of the header area from the Curtain Properties/Reinforcement tab. If the title region is removed in a curtain that needs to be created, the regulation condition is not met. The picture you added is not understandable. If you include the project file, we'll examine why the pitch header regions are different at both ends.