Why should it be not true? Planned maintenance is fully normal and certainly occurs on that infrastructure. The differences to normality are:

-- that sanctions have made the maintenance operations problematic: e.g. one turbine was held in Canada, and its release was agreed days ago only upon request from Germany. Why and how this process was impacted by the sanctions I do not know: it is what is reported by journalists;

-- that during normal operations, during maintenance on the main pipeline the gas is redirected to the secondary pipeline in Ukraine, hiding the technical works through such backup system. The secondary pipeline is inactive because of the war.