I tested with latest 4.4 branch and master branch, both work ok, I get in the logs:
``` 5(2974) DEBUG: <core> [select.c:412]: run_select(): Calling SELECT 0x10e6ff5b8 5(2974) ERROR: <script>: Variable is 1 in async route 5(2974) DEBUG: <core> [select.c:412]: run_select(): Calling SELECT 0x10e7021a0 5(2974) ERROR: <script>: Variable from other file is 1 in async route ```
Can you update to latest version in 4.4 series, it could be something that was already fixed. If still an issue, reopen.