I've bought multiple name-brand ones off Amazon, sold by Amazon. The one by my bathroom absolutely works. I can't count how often a steamy shower set it off. Were they buying knockoffs from third-party sellers?
> photoelectric smoke alarms should not be placed near bathrooms or similar locations that create steam. Even though location recommendations are already common on alarm packaging, nuisance alarms persist in homes due to inappropriate alarm placement
Which I suppose is on me, but it is a known issue with some smoke detectors.