Boomer doesnt respawn?

Im trying to find him and i have no idea where he is

I just got to that point now in the third playthrough.
Boomer appears as part of an optional mission available from Janey Springs in Concordia who invites you to investigate a distress signal coming from Outlands Spur.
The original mission is called Nothing is never an option.
The target area is at the bottom right area of the map which is the south east corner.
Leave the fast travel station, bear left and go through the garage with the DAHL sign above it where the pumping station flow control buildings are.
Continue on past the buildings and bear left again passing through an ice pass, fighting some Kraggons.
Use the air vents to gain height until you reach an elevated area at the end of the map where you will find some buildings.
If I remember correctly Boomer arrives in a Dahl fighter.

yeah careful where u slay that fella. dont end him when he isnt over land youll lose your loot, if he even drops anything…

i found the place but … Is there any kind of timer before boomer respawn? I tried to get out of the cave and go back where i can find boomer but he didnt respawn

Boomer is supposed to respawn after you leave the map and re-enter.
I completed that optional mission and checked in with Springs then recommenced mission progress and closed the game to take a break but later checked to see if there was a respawn
I just re visited the area where the transmission tower building is located and encountered 3 waves of Scavs coming over the cliff.
Each wave is accompanied by a fighter.
The last fighter is Boomer but I haven’t seen it close up because i immediately hit it with corrosive shotgun so it doesn’t last long.
I think it dropped a rubberised blue grenade mod with red flavour text.
Baby Boomer…BOOM baby BOOM!