Trying to match the most general choice at the end of the rule.

[urban-wombat]

This is a snippet written in the pest web editor:

Cell        =  { (float | int | String | InvalidCell) }
float       = @{ ("-" | "+")? ~ ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT+ ~ (("e" | "E") ~ ("-" | "+")? ~ ASCII_DIGIT+)? }
int         = @{ (("-" | "+")? ~ ASCII_DIGIT+) }
String      =  { "\"" ~ (!"\"" ~ ANY)* ~ "\"" }
InvalidCell =  { ANY+ }

What I want is for input that doesn't match float, int or String to match InvalidCell so I can report the error.
The Rust match statement on input includes all and only float, int, String and InvalidCell, in that order.
It hasn't matched InvalidCell with any of the input I've dreamed up, such as 222.3x3 which is an erroneous float.
(The pest web editor matches 222.3x3 as - Cell > float: "222.3" but that's not what I'm concerned about.)

Is there something obviously wrong with this grammar that I'm not seeing?