Popup: Not Shown Selected

Popup: Not Shown Selected
Hello, good morning. On my website, I use a lot of popups as teaching boards, but in “Edit Button” -> Link -> Link Options, I selected “Popup”. In the “Popup Settings” drop-down window, it only shows the first 20 popups. No problem up to this point, because I do a search there, it appears, I select it, and publish my page. The problem is: when I return to “Edit Button” -> Popup Settings”, etc., the selected popup no longer appears. It works, it opens, but it doesn’t appear selected. What appears is “All” (so you can reselect a popup). It seems to only remain selected if it was a popup created in the first 20; the rest don’t.