Windows changed, cracks appeared. Lintel issue?

SouthLondonHusband

We had the window frames in an old bay window replaced in the summer (new ones pictured below, since been plastered over). Since then, cracks have appeared in the mortar on the right hand side of the brickwork surrounding the window (pictured below, crack at the top and middle). Should this be a simple external repointing to fix the cracks, or should we be worried about the structural integrity of the bay since the replacement? As pictured below, the installers added wooden frames and there are joists on the left and right that come down from the loft, but no main central lintel.