Fixed capital formation is conceptually different

The former represents tangible assets
such as plant, machinery and building, whereas the
latter is financial in the sense of acquiring holdings in
foreign companies.

These financial holdings (for example
acquisition of shares in a foreign company) need not
automatically actually involve investment in plants
abroad.

Of course there is still a conflict of goals for an
individual company, whether to invest its money in new
plants at home or in a stake in a foreign company. But it
makes little sense to blame foreign direct investment for
any weakness of domestic capital investment, because
they tend to be complementary.