Hello,
existing and new table entries with 'umlauts' work fine with version 11.3.0.6449 After upgrading to 12.x and also the newest 12.2.0.6576 existing entries looks like they have a wrong encoding and it is not possible to save entries with umlauts.
The existing table has as collation 'latin1_swedish_ci' and I also tested a new table with 'utf8'.