Minecraft Bedrock Command block selecting a target with coordinates syntax help?
Selector arguments are in a key=value format, so you'll need to add x=, y=, and z= before the values.
You'll also need to specify a radius (r) from those coordinates to select players within.
The following command should work:
gamemode s @p[x=44.70,y=63.00,z=31.49,r=1]