Weired Number Format and Match

[animas]

I imported a data dump in a workbook.
I was trying Match fn. for matching a number in sheet1 with another nummer in sheet2. sheet1 formula shows N/A. When I select that number at sheet2 and clik F2 and enter, the formula in sheet1 immediately shows that match is found.

Why numbers acting this way? How do I know how many numbers are there in sheet2 which needs this F2 enter to show properly. What could the solution to this issue?

 

[VoG]

Maybe the numbers in Sheet2 are formatted as Text. Try selecting them, Data > Text to Columns and click Finish.

 

[animas]

i already checked that. It's number. Can't figure out the issue.