Text input inside submenu, text hints steal the mouse over

Hello, I have a login form inside a text widget in a MAX-MEGA-MENU submenu.
The problem I have is that, whenever a text hint appears in the user field, if you try to select it, the submenu looses focus and it hides.
Been trying to fix this, but I can’t, the only way I find is to suppress the browser hinting with autocomplete = off but this is HTML5 and may fail.
Any advice on this?

(The menu is inside a div with z-index 9000 and mega menu works at 999 level, but this doesn’t seem to be related)

https://wordpress.org/plugins/megamenu/