There IS definitely an issue on the German side of exports.
In order for a german gun to be exportable, it needs to be classified as "sporting purpose" or not based off a military gun. For example, the HK 416... The MR223 had to have the pin holes placed in different locations so they couldn't mate with a Mil Spec AR15/M16 lower. That's why the MR556 in the US has to be partly US made so it can use Mil Spec lowers (I'm actually not even sure if they are mil spec lower compatible or not)
We got the few of the fun guns into Canada, from movie deals or police department sales. They (Canadian gov. or RCMP) ended up passing laws that forbid the sale of used police guns to private citizens, not sure if movie companies are under the same restrictions.
They ARE in the FRT, non restricted or restricted depending on barrel length, so there is no problem in them GETTING into Canada, but HK Oberndorf cannot sell them due to German export laws, except for the guns they already have made as "sporting purpose" rifles.