Missing completions inside list comprehension

[danilaml]

Environment data

• VS Code version: 1.45.1
• Extension version (available under the Extensions sidebar): 2020.5.80290
• OS and version: Win 10 x64
• Python version (& distribution if applicable, e.g. Anaconda): 3.8.2
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A
• Jedi or Language Server? (i.e. what is "python.jediEnabled" set to; more info microsoft/vscode-python#3977): true
• Value of the python.languageServer setting: Microsoft

Expected behaviour

Same as outside list comprehension - you get string methods in completion prompts:

Actual behaviour

No completions are suggested:

Steps to reproduce:

1. Just type the following code in VSCode and try to call a method of t (same in filter condition).

tst = ['abc']
[t for t in tst]