Hi Graham
No problems here with 2015. I tried copying 4 bars, then 8 bars
This was my setup (check your check-boxes settings compared to mine)

Attached Files (Click to download or enlarge) (Only available when you are logged in)
2015-01-03_00-11-13.jpg (68.95 KB, 39 downloads)
2015-01-03_00-09-07.jpg (69.04 KB, 39 downloads)

BIAB & RB2026 Win.(Audiophile), Windows 10 Pro & Windows 11, Cakewalk Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Session Keys Grand S & Electric R, Kontakt, Focusrite 18i20, KetronSD2, NS40M, Pioneer Active Monitors.