We have install ArcGIS 10.5.1 on one of our PC recently. I have joined admin polygon with xls file. Then when I open the qury builder, I see the following and the same is true when I open attribute table and label expression. Please any help on this issue

[ZelekeKebebew]

[JayantaPoddar]

I feel the Join is not correct. Could you check the number of Features (Matching Records) when you Validate Join.

Share the screenshot if you get any error message while validating join.