The resulting flight path of this bug is a very common one. Going through the localizer and then turning back to re-intercept. And it's in the standard operatin

The resulting flight path of this bug is a very common one. Going through the localizer and then turning back to re-intercept. And it's in the standard operating procedures for every airline/operator to monitor loc capture by the crew. This "oops it didn't capture" also happens when you forget to select the right autopilot mode, which isn't an uncommon mistake for pilots in training. It's actually so common that at airports with two runways close together they make aircraft capture the two localizers from different altitudes so there is no risk of collision when they fail to capture. (For example 18R and 18C in Amsterdam capture at 2000ft and 3000ft, this is done nearly every day) So I'm going to say: Not really a big deal in terms of safety, easy to handle for the crew. But absolutely worth a safety report since unexpected auto flight behaviour needs an investigation and correction.