My understanding is that Venus, Earth, Mars, and Jupiter are all losing mass due to their gravity, temperature, and the solar wind. But what about Mercury, Saturn, Uranus, and Neptune? Mercury has a magnetic field and so typically would repeal the worst of the solar wind and no atmosphere to lose, only an exosphere. Though the Poynting-Robertson effect should be pulling in more dust to Mercury. I do not know the calculations to determine if Saturn, Uranus, and Neptune are losing mass though.
I'm not sure how the balance between mass loss and gain works out...
Yes, atmospheric escape is probably happening to some extent on all the planets, with rates that depend on escape velocity, magnetic field, atmospheric/exospheric composition, temperature, and other effects we are still learning about.
But the planets are also gaining mass by capturing dust, meteorites, and the occasional larger object that can cause cratering on solid bodies, or atmospheric debris clouds in giant planets like Jupiter.
Anything that's working, spending energy is losing mass, Einstein Mass-energy equivalence of SR along with radiant energy(electromagnetic and gravitational radiation) would be effecting all the planets, but at a different rate for each one. https://en.m.wikipedia.org/wiki/Radiant_energy
And. https://en.m.wikipedia.org/wiki/Mass_in_special_relativity These should help I think