To reproduce: Go to Administration > MARC Cataloguing Frameworks and then MARC structure for one of the frameworks. Go to Edit tag for any tag and add a default value to Indicator 1 and Save changes. Tick and untick 'Display only used tags/subfields' and notice that the second indicator value is incorrect when this is ticked. Add default values to indicator 1 and 2, the second indicator will be replaced with the value in indicator 1.