You are not the first to report something like this. Use the new Track View to see exactly what track (instrument) is playing this noise. That may provied a clue to a fix.


BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, 1TB WD Black NVMe SSD, 2TB WDC Blue SSD, 1TB WD Blue, 2 TB SK NVMe, 6 TB External, Motu Audio Express 6x6