Recently Mazda have finally made a recall for the push nuts failing on the gen 2 seats. They have also said there are safety issues with the boot gas struts.
You can check here if your car has outstanding recalls but it won't tell you which, you'll have to ring your local Mazda to get that info and get your car booked in for a free repair
https://www.themotorombudsman.org/vehicle-recalls
Apparently with the seats they replace any missing push nuts and they put a new bracket in which stops them from coming off again. Hopefully no more wobbly seats!