Why not build a 3rd level menu?

Question

1C-Bitrix

I need a menu that has three levels, the first two build well, but not the third one, I can't figure out why.
Folders and menu files in them are lined up correctly and double-checked a hundred times, the settings of the menu component are also correct.
I even included the default horizontal_multilevel template for verification, in order to know for sure that I didn’t spoil anything in the template.
Mb someone faced?
This is not the first time I have done this menu, but this time I don’t understand what the problem is ..

Answer 1

Are there elements of the third level in $arResult in the template?

Answer 2

To build the 3rd level, you need menu files located in folders at the addresses to which there are links from the 2nd level menu. Level 3 menu type should be the same as level 2.