Batteries would likely not be a customs matter. It’s an airline safety concern. If they shipped batteries that did comply with the packaging and declarations regulations, that would be treated as a serious matter. It can, and has in the past, killed people.
However, common sized lithium ion batteries shipping inside the device they are used with have reduced regulations, which is why some sellers will offer batteries with a flashlight, but only up to the capacity of the flashlight (and with insulators on one of the terminals to prevent activation.
I still think it is likely that anything shipped by the lowest priced service is only getting through sporadically due to the shortage of air freight capacity, and not reliably in a first-in, first-out manner. And items may be getting returned to shippers that in normal times would not be stopped, simply to reduce the backlog.
Even just considering Sofirn’s products, and not comparing another company like Twosun, one flashlight might arrive at the sorting facility on a day when all the flights are full with higher fare cargo. The next day more packages might not have flights and get dumped on top of yesterday’s packages, burying that flashlight. After a week of this, another Sofirn flashlight might go on the top of the growing pile, but be the first thing grabbed when a flight has room for more bargain fare packages, while the light that arrived a week earlier takes several more weeks to unbury.
