Join tool duplicating all of a sudden?

[ALLSEBS01]

Hi all, 

I was wondering if anybody could help? I've had a workflow I've been using for months a few times a week, nothing has changed on this and the process and files used for the workflow hasn't changed either. 

I have a sheet which has 5 records which is correct, however once it is joined with another sheet which I want to add one column from, it returns 10. It's only just started doing this? has something on the join tool changed? 

I have put a few images, and one of the workflow. The example I've given is looking at the ones which are true to separating mismatches.

Thanks, 

Sarah

[Raj]

@ALLSEBS01 
it does not seem anything incorrect in configuration

will you be able to copy the sample records on new sheet and copy the same join tool from your canvas to check if it is giving same result

in case you are still getting error please attach that sample workflow

[alexnajm]

Nothing has changed behavior wise in the Join tool, so it must be the data - make sure your data doesn’t have duplicate keys as that will cause the records to duplicate (the screenshot you have seems to indicate multiple records of the same key but checking the other source will be important too)