Style/HashSyntax reports errors with string interpolated Symbol names

[arbox]

Rubocop reports style check violation while processing hashes with symbol keys coming from string interpolation. See examples below.

Expected behavior

No errors reported.

Actual behavior

Error reported (in FlyCheck/Emacs notation):

Don't mix style in the same hash. [Style/HashSyntax]

Steps to reproduce the problem

Having the following Rubocop configuration:

Style/HashSyntax:
  EnforcedStyle: ruby19_no_mixed_keys

try to write:

{"#{accountant.id}": {number: "4711", name: "Test"}}
{"#{@accountant.id}": {number: "4711", name: "Test"}}
{"#@accountant.id": {number: "4711", name: "Test"}}

RuboCop version

We're using the latest Rubocop for these examples:

$ bundle exec rubocop -V
0.65.0 (using Parser 2.5.0.3, running on ruby 2.4.3 x86_64-linux)