Columns returning null after merge

[Rozlynmac]

I am merging two tables (retain table 1, add new columns from table 2) using a left outer join. The 'id' field in each table is correctly formatted and the merger returns 34k+ matches which is as expected. All of the merged columns are present and visible in the merged table.

One column which is formatted as text in table 2, has around 200 null rows in the column, the rest containing alphanumeric strings of 4 to 7 characters. (This is not the only column containing data in this format.) Here's how the data looks in table 2 before it's merged into table 1

But post merger, no other transformation steps taken except to expand the new columns, All rows now show only null with the type heading showing '?' 

As it's the only column in the entire table doing this, I can't figure out what has gone wrong.

[ray_aramburo]

Are both columns used in the merge having the same data type? Also, have you checked in that column if there are other values that are not null?

[Rozlynmac]

I'm merging about 30 columns. The 'id' field being used for the merger in both table 1 and table 2 is correctly formatted and is matching properly. All other columns being pulled in via the merge are correctly populated after the merge. Before they are merged, the column in question is fully populated barring around 200 rows which are at null, all other rows contain data. After the merge all rows in that one column contain only null.

Thank you.

[ray_aramburo]

Is it possible for you to provide the .pbix file?

[Rozlynmac]

I tried to recreate the error in a smaller dataset with only the rogue column and the ID column being merged and it populated correctly. So it looks like it's somewhere else in the data that is causing the issue. I'll keep digging and share something if & when I can.

[Rozlynmac]

Unfortunately not. It's protected data. But I can try & create a smaller version with non-protected data and if it happens still I'll share that.