Think of it this way: if solar-flare magnetic aberrations could be strong enough to make an effect on humans, then they would also affect other things that are far more sensitive to magnetic fields.

For example, a VHS tape, audio cassette tape, or an HDD computer hard drive (they store data on spinning magnetic plates) would be erased or at least damaged when exposed to a normal household magnet.

Additionally, if you consider the argument that somehow humans are even more sensitive, then a normal household magnet would cause similar symptoms as the claims of Heliobiology and we would see much worse with stronger sources of magnetic fields like an MRI (magnetic resonance imaging) which could even pull a metal chair across the room.