Alter drop column on table is very slow

We are having performance issues with the following drop column statement in production.

alter table tbl_rt_request_event drop column message_clr;

The table has 13.4 million rows. The column getting dropped is CLOB and is only 0.125MB in size.

The drop column is generating lot of archives and not completing. v$session_longops shows this statement is expected to run 11+ hours.

The same drop column in other 2 production databases did not have the issue.

One database with 5.8 million rows for same table, the drop column completed in 1 min

Another database with 2.3 million rows for same table, the drop column completed in 25 minutes.