IF function not returning results every time

Question

I need "Yes" to be returned if the data in C2 matches A1:A12 on Sheet 2 and if not return "No".

I entered this function:

=IFERROR(IF((VLOOKUP(C2,'Sheet2'!A1:A12,1,TRUE))=C2,"yes","no"),"")

This only works part time, the data on sheet2 in columns A1:A12 all start with the number 7. In testing I have found if I enter a number in my reference cell, C2, that starts with a 7 or higher I either get "Yes"/"No" depending on if it matches one of the cells in sheet2 A1:A12 (working as expected). But, if I enter a number that starts with a number lower than 7 the function errors with no result. Not sure what is causing this.

For example:

If Sheet2 A1:A12 contained

7500
7503
7504
7705
7507
7509
7568
7745
7747
7748

If I enter 7503 in cell C2, it would return "Yes"

If I enter 7777 in cell C2 it would return "No"

If I enter 9999 in cell C2 it would return "No"

If I enter 5306 in cell C2 nothing is returned

If I enter 1111 in cell C2 nothing is returned

Answer 1

For VLOOKUP with TRUE as 4th argument, the lookup range 'Sheet2'!A1:A12 should be sorted in ascending order.

But 7705 in A4 is lager than 7507 in A5.