I’ve been running on less than 200V AC most evenings for the last 18 months. Weird stuff was happening to my linear amplifier and I was getting higher output during the day to the evening. To cut a long story short, Central Networks have just completed a complete re-engineering job at the end of our cul-de-sac with a new transformer and new feeder. Amazing what you can get done if you are polite (not a strong point of mine).
Have you checked your AC at peak times? You may be surprised.