I mean, there were riots last month and then the last time I recall riots before then was 2019 when the journalist was shot. There might be more inbetween I’ve forgotten but a cadence of 5 years is more than the ~10 year cadence for mainland UK (which is culturally very similar). Sectarian tensions have died down in the past 20 years - my sister is currently in Belfast and loving it - but they still exist and have deep roots.