usually i prefer dist-upgrading apt and dpkg before everything else
(right after `apt update`).
always thought that newest apt is more compatible/tested with new
releases.. never really looked/asked if that's true though (...), just
a personal "habbit" over previous years of dist-upgrading :)
--
problems described above sound like debian bugs though, maybe debian bug
tracker has similar issues to look up..

2c,
d.