Sum a field based on a multiple choice field

I am trying to sum a field based on the value of a multiple choice field, ie = 1, 2 or 3. This works for values 1 and 2 here

sum((select 'Personal details')['Bond/Insurance Provider' = 1].'Total amount lost in GBP')

sum((select 'Personal details')['Bond/Insurance Provider' = 2].'Total amount lost in GBP')

but comes up totally zero for 3

sum((select 'Personal details')['Bond/Insurance Provider' = 3].'Total amount lost in GBP')