k p c writes:
> Seemingly, headers matching neither vm-visible-headers nor
> vm-invisible-header-regexp are not being displayed. They should be
> displayed at the end of the headers instead of not being displayed.
> This bug was apparently introduced in 5.34. Since a change was made
> in 5.34 to hide headers that match both, perhaps by mistake vm was
> also made to hide headers that match neither?
Exactly. Fixed in 5.36.