Using Arc Pro 2.82
I have built a fairly simple tool. It allows the user to create a feature class from a feature class with an expression, then to apply a symbology (.lyrx ) that changes both the symbology and labeling, based upon the values in the selection. Lastly the user can name the output.
Running the model, from inside the model builder it works as expected.
Running it as a tool, I get the expression, the output name and the labeling but none of the symbology.

The layer titled Test_S2NV was made run from the tool window-Left. It displays on the with no symbology , but with the expected labeling.
The feature labeled Updated Input layer Test S1NV displyas as expected. It was run from the run button in the model builder.