As to previous versions, I don't know; this is a new use of the tool for me, and I no longer have an older version installed, though I expect (see next answer) that this is not a new issue.

An all MIDI (in particular, EZDOESIT) seems to perform flawlessly, and using one such will solve my issue. I will also experiment with tempos per Noel's comment below; it could be I'm asking the real tracks to do things they simply can't do.