I can't provide a MWE (too difficult to reproduce) so take it as a general question, please:
How can I prevent reledpar generating widows? I read that I could prevent orphans by manually inserting a pagebreak, but what about widows?
Sometimes in my right page (and just in the right!) I get the last row of a paragraph which should be in the previous page.
ATM I'm using just the shiftedpstarts sync option.
I have the same problem in the Endnotes... how can I fix it?