Their customs or shipping controls are probably actually checking things more thoroughly (because they are being checked more thoroughly at destinations?), and now requiring htem to follow the rules, actual certifications/etc. to ship things, and not allowing "toy" as a description for all this stuff anymore. Or they are charging new taxes or fees, raising the prices beyond what these companies had originally gotten away with.
Air freight of batteries is now very expensive, requires certifications by the shipper, etc., and at least here in the USA it's getting hard to even get a shipper to accept batteries at all, even for ground shipments, probably because of the incidents that have happened from poorly constructed/designed/etc packs sent either by themselves or as parts of objects ("hoverboards" come to mind).
It could be something else, but that would be my bet: that the shipping methods previously used can't be anymore, and now it costs too much to ship them.