How does my lintel look?

[Caz6]

Novice here, so some stupid questions first. I assume the blue steel beam I'm seeing between the window frame and bricks is the lintel yes??
As you can see from the picture there seems to be a gap between the this lintel and brickwork...around 1 cm in the midpoint. The window is 3.6m wide, quite wide by modern standards I think. On the inside, there are some cracks in the plaster along the width of the window about 10cm up from the edge.
The house was built in 1969. We had a fairly thorough survey done when we bought the house, but this wasn't mentioned. Any opinion as to how worried we should be?? How easy is it to fix a sagging lintel? We intend to change the window next year, possibly bricking it up to waist level, but keeping the width.

View media item 9734
View media item 9735
View media item 9736

 

[^woody^]

The lintel was tight on the old frame and when the plastic window was fitted the front of the lintel has sagged. The cracks at the bearing are most likely related to the window fitting too.

Its not a problem, the wall has stayed put and the lintel is not going anywhere.

Just repoint it.