I have been noticing more often that lightning rods do not protect surrounding wood-type blocks from igniting on fire.

As the lightning rod was introduced in 1.17, its primary function was to attract lightning to itself, preventing rooftops from catching on fire, since this was an issue before. However, as I observe the lightning strike the rod during thunderstorms, fire particles tend to spread to surrounding blocks, often destroying them. I have noticed this issue in previous versions before 1.18, but didn't notice it as severe. After coming up to the surface after some mining, I noticed one of my builds partially destroyed (the wood). I remember hearing a thunderstorm while I was undergrown, so I'm positive that it happened then.