I'm reporting this as I believe there are  potential consequences for user's
security and privacy.

When system resumes from suspend, there's a small 1-2 seconds delay before
prompting a lockscreen. Within this delay, the content of the desktop before
suspend is fully visible, same as if it was unlocked.
After 1-2 seconds, it shows the locked screen. 

I tried with several lockscreens such as xscreensaver and light-locker but the
result is always the same. 

I suspect it's a race condition.

Steps to reproduce:
1. Suspend system through menu or by closing laptop lid
2. Resume by pressing the power button or by opening laptop lid
3. It should be expected to see a lock screen but instead desktop content is
shown

I've tried to make the lockscreen load before suspend through a systemd service
but I did not succeed.