I have use the "Copy internal link" to connect one note to another. When I subsequently display 1 or the other

[FrankMundo 0]

note SOMETIMES there are they  have th " <  >" controls in the upper right corner (that allow me to move back and forth between the two notes . . .  and sometimes they are not there so I can not move back and forth between them.  I cannot figure out why this works consistently and sometimes it doesn't.  What is going on here?

I thought this was a "screen size" problem, but it is not