Would suggest perhaps something's grown on the lens from spores(?). Perhaps the addition of water was enough to activate them but not to remove the spores. Or possibly crystallisation from a solution around seed points? Those star shapes definitely look like either something living or something crystallised out of solution. But am really no expert at all - though I've seen 1cm lichens growing on an old uncleaned primary mirror that was left for a decade
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The more I look at it, the more it looks like crystallisation - maybe salts from the water, or produced by the mix of water and whatever was on the lens surface pre-cleaning?
I hope you can find a way to fix it!