The turn-on transients of the aircon could exceed the maximum output power of the SBV. Its surge current limits are very close above its nominal output. If those are exceeded, the device drops the output voltage for 1-2 seconds or however long it takes for the overcurrent situation to clear. In 230V countries this would make light dim noticably but usually doesn't affect electronics with switch mode power supplies, however in 110V countries, this might cause more issues.
