OS: All
Build Version: 20230523.2

Repro Steps:

1. Create a Python V2 Programming Model project with HTTP trigger template function.
2. F1 -> Create Function... -> Select HTTP trigger template -> Select "Append to function_app.py" -> Enter a function name same with above function.
3. Check whether an "xxx already exists" validation message pops up.

Expect:
An "xxx already exists" validation message pops up.

Actual:
No "xxx already exists" validation message pops up.

More Info:

1. There is no error in "Problems" after adding 2 HTTPtrigger functions with the same name.
2. An error occurs after deploying a project contains 2 HTTPtrigger functions with the same name.