Sorry, my fault. I retested again now and for some reason I had 3.0.5 dangling running in Windows (surprisingly without an icon in the tray). Using really 3.0.6 snapshot everything is fine.
-- Mgr. Jiří Činčura https://www.tabsoverspaces.com/ Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel