Hi
Text strings which contain spaces should be enclosed in double quotes. e.g. from the manual:
You must enclose each operand in double quotes when comparing operands that may contain spaces. E.g.:
Selection's Name is equal to "Marine Captain"
for ease of operation and consistency you can also enclose strings without spaces in quotes. See attached screenshot which I used when testing.
I tested UK and US at the same time in a marketlocator template using "any condition must be met". It pulled in all relevant markets.
Your trigger conditions are fine, however, amount for UK races is well below Betfair minimum, and depending on size of your bank, US races bet amount also below minimum. Confirm in your settings for betting options that small bets is allowed.
Otherwise trigger works well.