This is already a well known fact: protein structure (and consequently function) is much more conserved than sequence, mostly due to biophysical constraints.
If non-synonymous mutations do not change the biophysical features of the amino acid residues, then the structure is usually kept. Alternatively, it can be the case that a disruptive mutation is compensated by another one that keeps the structure/function/phenotype. This is the basis for evolutionary coupling based structure prediction methods, such as Alphafold.