Yes, I have this same issue of not being able to force myself to read certain texts linearly. Menus really are difficult, and I often hear a friend saying they’re going to order something I swear was not even on the menu but then they point it out and I see I just erased it when I was reading.
It often depends on my emotional state, and being hungry or tired makes it worse, which makes menus even more difficult. When it comes to instructions, I usually just look at the pictures instead of reading, which works for Legos and IKEA furniture. My suggestion would be to eat a snack or make sure you’re tackling instructions at the time of day you are most alert. For menus, can you look at the online menu ahead of time? I find that usually helps me to know what my options are in advance, and reduce the pressure of making a decision while hungry. I also usually find online menues easier to read for some reason.