To allow for proper drainage.
Make sure it is not a “drop plate” beam first.
Useless if it is actually split .
caulk that vertical freeze board
That mullion should be able to carry that load.
What is not seen to complete ones hypotheses needs to be addressed.
That being said.
Good observation of the brick veneer. Bravo.
Questions I ask myself.
I have a boar-scope.I would try to get behind the element any way I can.
Even a metal prob to feel for the plate.
Was it welded in the back?
If not, it will cause degrading. Live or bed load issues will arise.
Now above the intersection ( the two lentil ) ( the soldier patterned brick ) up to the next BOND ( stretcher ) and every course after that going up to the next load bearing point if there is one.
Objective; signs of stress?
Even if there is a load shelf, is it continuous across the plain?
The load shelf ( lintel ) fault can be transmitted across the entire field.
A window above the fault?
The cracking ( the fault ) will find its path along the weakest horizontal and vertical lines.
That is the masonry bedding, butt and head joints unless 1.) brick is flawed there is so much force loading, the bricks tensile strength will not carry the load.
It will break.
Is there another shelf?
It will move around openings in the exterior wall and continue.
Over time weather driven horizontal forces and vertical live and dead loading start degrading all components involved in the exterior envelop.
Can be as thin as a piece of human hair. You need to be on-top of that butt joint and follow bed and butt joints and up close YOU CAN as they move upward.
CLOSE. 6 INCHES AWAY OR A GOOD CAMERA WITH 24 TIMES MAGNIFICATION…
Look for; Offset brick plains,( not parallel in line ) or on the same horizontal line.
Missing masonry in the head, butt or bed jointing?
Look up vertically against the side of the building at several angles.
Your head against the wall and move it away up to 6" and back-again slowly!
Look up the wall as close as you can and move you 180 degree line of sight back and forth ( up to 6" ) no more for now, to see small or large offsets vertical offsetting.
Best place to practice is a intersection. A 90 degree corner.
You will spot the imperfections in plumb.
Here is what you are looking for.
This as a large example.
The shelf is separated.
Even if there was a plate welded to the back it still can flex horizontally.
1.) Cracking in masonry butt joint above the separated lintel.
2.) Missing masonry between the 7 and 8th clay brick solider header.
Weeping system in headers are dependent on the layout.
I would call it out.
Unconventional brick self or lintel.
Recommend licensed mason install a lintel.
Minimum 4" inch bearing on brick.
Look at the brick ( side face lead edge. )
The vertical line at the opening…
It is not plumb.
1/16’ % degree in variation in plumb or vertical line is allow in masonry building.
Poor brick masonry practices.
Open voids; Vertically driven weather will degrade components at an accelerated rate.
The wider the opening, the faster the degrading process.
I would charge $1000 dollars to repair that properly.