For me the line below the board does appear, in the Comments listing:
Sometimes multiple Diagrams in the Comments listing would interfere with each other. E.g. because one links to betza.js and the other to betzaNew.js, or because a page contains other JavaScript. In that case viewing it in isolation through the View link solves the problem. But it should not be necessary here, as I don't see any other Diagrams.
The only other explanation I can think of is that the script crashes between creating the board and the subscript line. Because of something that is present on the page of the Comments listing, but not elsewhere, and on your computer but not on mine. I don't know what you would have to do to get to see a JavaScript console on an iPad (like I would get by pressing F12 on my PC with FireFox), but if there is a JavaScript error it should give an error message there.
For me the line below the board does appear, in the Comments listing:
Sometimes multiple Diagrams in the Comments listing would interfere with each other. E.g. because one links to betza.js and the other to betzaNew.js, or because a page contains other JavaScript. In that case viewing it in isolation through the View link solves the problem. But it should not be necessary here, as I don't see any other Diagrams.
The only other explanation I can think of is that the script crashes between creating the board and the subscript line. Because of something that is present on the page of the Comments listing, but not elsewhere, and on your computer but not on mine. I don't know what you would have to do to get to see a JavaScript console on an iPad (like I would get by pressing F12 on my PC with FireFox), but if there is a JavaScript error it should give an error message there.