High consumer voltage is now the BIG problem.
Ten or twenty years ago the main voltage complaint from domestic customers to electricity suppliers was occasional or perhaps persistent low voltage. We developed the EC-1V, a single phase voltage logger to measure and record the delivered voltage. This was and is used by many power companies around the world. Many companies then wanted to also record the customer's current draw, to see if any low voltage was caused by taking too much current, we developed the EC-2VA for this purpose. If the problem is reported high voltage, then you need only record the voltage with the EC-1V.
Over voltages are generally caused or exacerbated by onsite or locally based renewable generation stations, PV, wind or sometimes hydro. The problems that over voltages cause are tripping of solar inverters, solar hybrid inverters and battery charge and management systems and other sensitive onsite electronic equipment within the property. Often affected devices are owned by the complainant, their first indication of a voltage problem.
If the complaint is over voltage, the recent phenomena, you can revert to voltage only recording, as it arguably not (as) important what the customer's current draw is! What is indeed relevant is whether or not the customer has (or is in the neighbourhood of) renewable generation, such as solar PV, wind turbine, hydro or other. It is also important for the electricity suppler to ensure that the onsite generation is turned off during the voltage logging period. This allows the actual delivered voltage to be recorded, uninfluenced by the local generation. If the customer's voltage is recorded with the embedded generation on, then the voltages recorded do not (not) represent the supplier's delivered voltage.
On occasions owners of embedded renewable generation stations are reluctant to turn off the generation as this is financially damaging to them, they will not get paid while they are not producing electricity and may have to purchase from the grid at unfavourable prices.
The network operator will want to record the delivered voltage for at least a week but can't or won't do it while the renewable station is generating as it is likely 'forcing' the voltage higher. Often the customer is sometimes reluctant to turn the generation off to allow the network operator to measure the voltage as this reduces generation revenue.
My first suggestion is to measure the voltage on site with the station generating (enabled), this gives an indication of the extent (or otherwise) of the problem. If the voltage is found to be high, the next step would be to record the voltages over a week with the generation turned off (disabled). Then based on those findings a conversation can be started with the network operator, but if the voltage is high the likely next step would again necessitate the removal/stopping of generation for a week while the network operator records their delivered voltages.