Try this: take one of those pans, put it on something known-flat (like your counter). See if there are any high spots or if it sit exactly flat. If it doesn't sit flat, then it'll be problematic on induction.

From the pan in the picture, I'd guess you're not on induction (most alu pans, except those with a built-in ferric grid, don't work on induction). I can't use my copper cookware on induction (it's non-magnetic like alu).

That said, it also sounds like you aren't rinsing your pans well after washing them or aren't rinsing them under running water. I ran across dish soap in New Zealand that purported to not need rinsing (many homes there are on catchment water supplies) but I couldn't bring myself to actually not rinse so I've no idea how well it works