Hello,
Apex 20.2.0.00.20; Listener 19.4.6.r1421859; Oracle 18c XE
Reporting a potential bug.
Setup: A page with classic report (value attribute pairs - column) with REST source. Added a column manually to REST Source. Clicked Synchronize Columns. No column was added.
However, the parameter (i.e. filter, value = PL/SQL Expression Language=SQL) was cleared out and set to NULL. NULL is a default value of a REST Source parameter. Though at the report page it was populated. This might be by design. However, I would expect the parameters not to be overwritten. I could see the other point too.
Also, I do see a new column added to a COLUMN parameter, but not the report columns. So, parameters get synchronized, but not actual report columns.
Thanks for looking into this. Unfortunately, I have not tested this on apex.oracle.com. It might have been already fixed.
Workaround is to recreate the region.
Thank you.