"firmly connect" is a perfectly correct and usable phrase in written English.
You can use it to refer to a strong bond, link, or relationship between two or more people, organizations, or ideas. For example, you could say: "The two groups were able to firmly connect and develop a plan to move forward."
I don't know what specifically they did not like, but I firmly connect this with his professional activities".
"We firmly connect Hitler's text with our comments, so that both are always on the same double page.
The dominant reason for the improved photocatalytic reduction potential is proved to be the newly-formed interfacial SZn bonds that firmly connect Cd0.5Zn0.5S and ZIF-8 and substantially improve the separation efficiency of photo-excited electrons and holes.
As she loses track of herself, the book finally breathes, as if it took that encounter with something as elementally real as Charles Mingus's dying to firmly connect her to her identity.
The challenge in creating the new first world war gallery at London's Imperial War Museum was how to create a "felt" experience that would engage the attention of younger, increasingly distanced and in some cases desensitised generations: how could we evoke authentic emotions that would firmly connect the contemporary visitor to a 100-year-old story?
Until, of course, I close my eyes, feel my feet firmly connect with the floor beneath me, and take an anchor breath.
Thurber's name is firmly connected to Columbus.
The house is also firmly connected to the past.
In other words, Mondrian, like Stout, remained firmly connected to nature and the real world.
"What also matters is that they are firmly connected to family and friends," says Jagger.
TEM analysis showed the presence of graphene flakes arranged parallel to the substrate surface, firmly connected to the porous coating.
