Google Chrome	69.0.3473.0 (Official Build) dev (64-bit)
Firmware Version Google_Lulu.6301.136.57

Steps to repro:
# Pair Bluetooth headphones, I am using charged up JVC Bluetooth headphones. See normal pairing and re-connection protocol below.  

# Shut off Chromebook and leave it off for a few hours. This does NOT reproduce if you turn off the machine and turn it right back on again. 

# Turn Chromebook back on and turn on the headphones. 
 
# Go into Settings > Bluetooth, under Paired devices, click on the JVC headphones. 
# Listen for connection beep, play music locally (I just use a YouTube video but repros with any audio)
Expected: music plays through headphones 
Actual: music plays through computer speakers

# Headphones make a second connection beep but it still didn't connect
Expected: music plays through headphones 
Actual: music plays through computer speakers

Workaround: delete the JVC paired device in Bluetooth settings, power cycle the headphones, and pair as if first time setup 

Frequency: This has happened the last three days in the morning after the machine was shut off overnight. 

Typical pairing for these headphones: to pair the headphones, you hold in the power button until it says "pairing". On the Chromebook side, go to Settings > Bluetooth > look under Unpaired Devices and click on the JVC headphones listed there. Software indicates it is connected. After a few seconds, the headphones make a connection beep indicating successful pairing. 

Typical connection for these headphones after pairing: on the device, make sure Bluetooth is on. Turn on headphones which should automatically find the device. After connection, a beep is heard and sound comes through the headphones. 

This does not reproduce on a Pixel 2 phone so the headphones are known to be working.