that's because in Europe there is 9mm or that weak American stuff."...check with the maker..." Yep. Not all of those manufacturers' products are rated for +P pressures.
SIG, for example, doesn't mention +P in relation to any of their stuff in their advertising. However, 226 and P320 are used by the military with 9mm NATO. 9mm NATO is considered to be +P by SAAMI.