WIFI is not working after some time when screen is locked

The problem

WIFI is not working after a certain time passes when screen was locked. Apps which rely on WIFI connectivity are not working (KODI remote, WhatsApp Web, etc.) until the Wifi comes back to life when the screen is unlocked.

After then, everything works seamlessly.

What is the expected correct behavior? Wifi connection is not being turned off when screen is locked. Any app which relies on WIFI connection should work as intended (being able to transfer data via WIFI while the phone is locked.)

Technical information

/e/ Version: 0.12-p2020093076095-dev-FP3

• /update: Still an issue on 0.17-dev-FP3
• /update: Still an issue on 0.21-dev-FP3

~Bug FP3