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It suggests the code you are breakpointing is not included in the final link, likely due to dead-code removal.
For an "urgent" problem you provide little material detail to work from.
I might guess you are breakpointing an IRQ Handler, which isn't correctly named via the vector table in startup.s, or that you have code flow that never gets to this point, say due to a while(1) loop blocking forward execution, or logic that precludes operation, ie if (1 == 0) not_happening();