In Desktop, when you set up a Relate between tables, it worked in both directions.
In Pro, when you set up a relationship, it only works in one direction. It is not a huge deal, but an annoyance to have to create a relate from table A to table B, and then have to recreate a relationship from table B to table A.
When I receive a table from someone to use in a join, I like to confirm the cardinality, if there are duplicate values, and if all records will have a match by using relates:
1. Create a relate between the tables.
2. Select all the records in the table I am exploring, note the count of records.
3. Hit related records, to have the related table pop up with related records selected. Note the count of records.
4. Hit show related records in the original table to see if the count is less than the first time. ***Nothing further was needed to do this step in Desktop. Now in Pro, you need to create the relationship back to the original table***
in one and see related records in the other table and visa versa...
I hope there's a good reason that I'm overlooking for this "feature change" aka reduction in functionality??