you can overcome the bug with a -64 VOL trigless p-lock on the first step of THRU for the new pattern.
-OR-
you can deal with AMP ENV settings…
it’s up to you 
I strongly suggest you to deactivate the global option SILENCE TRACKS.
Use instead the START SILENT from the Pattern menu…of course, not on THRUs. But it is still ok for other kind of machines.
When a bug comes , the workaround is just around the corner. And OT has many corners…ahahaaha