Things like this usually gets complicated when it is put in a library.
Without the actual model, I could guess:
- If you are setting the Constant block value using set_param() based on the selection in second Popup, then this is the wrong implementation if you want to put it in a libarary. Instead, you should set the value of the Constant block as "Pop2" and name the parameter for the second Popup as "Pop2". In other word, pass the masked parameter to the Constant block.
- If you have to use set_param() to set the value of the Constant block, then you need to add a callback to the CopyFcn of the library block, which will automatically disable the library link once the block is dropped to the model. This is not ideal because all the library links will be broken. But it had to be done if all the blocks dropped to the model end up differently due to set_param(). Remember, all the blocks in the model are supposed to be an exact copy of the library block except the allowed parameters. If your blocks in the model end up diffrently due to the selection in Popup in the mask, then you have a problem and you have to deal with it accordingly.
- Look for "Parameterized Links and Self-Modifiable Linked Subsystems" in the document. I believe your issue stems from this topic. Option 1 and 2 above are easy solutions if they are acceptable. This document should provide full details.
