It is normal for the voltage to drop at peak times when people start cooking meals etc. In England I remember the voltage would drop when the adverts came on the television as people went to put the kettle on for a cup of tea.
My UPS that connects the power supply to my computer registers the supply voltage and warns me when the voltage falls outside the specified range. On a few occasions it has been high but more often it is low.
Yesterday it warned me that the voltage had dropped close to the 208v limit which is remarkably low for a supply of average 240v. It could explain why some residents at Villas Andrea have problems with some of their equipment including the larger air conditioning units which run off three phase electricity.