Ctrl+Shift+B Shortcut Applying Semibold Instead of Bold in InDesign

The fix is not to use this word-processor-based poor practice (spot formatting content). It's a feature that really shouldn't even exist in InDesign, and is implemented only by some key shortcut assignments.

As Willi noted, you should never use spot/ad-hoc formatting in InDesign. Create proper styles for every override, including bold, italic etc. If you then want to assign the key shortcut to applying those styles instead of a local override to "bold" etc., feel free; it's both convenient for those of us who write in ID and follows good practice as well.

(In fact, I often use it when I want semibold as my "bolding," in fonts that have too hefty a bold face — and even if Bold is okay, Semibold Italic is often more esthetically pleasing than Bold Italic. Being able to throw a tiny bit of tracking or other tweak can help match the highlight to the body text better as well. So the ability to custom-map your text highlights is a great reason to use proper character styles, not crude ones taken from the Word [processor] model.)

If you prefer a more direct answer: it's probably font related. For some reason, ID considers the font's Semibold to be the right "bold." You can change it by remapping the shortcut key to Bold (and it may be that something set/reset the target to Semibold in your defaults, causing the mixup in the first place.) But the better solution would be the above — create and refine your own override styles, and apply those with the shortcuts instead.

In InDesign you d not have automatically appplying styles. You have to select a font style of a fonz family which must be available installed. Create a character style with this font and apply this charactre style. Never work without patragraoh and character styles.