I bump this again, because with 5-27 - 5.28prexx overlapping notes are not possible anymore.
Together with swap the edit view and or re open item
(and this is important: if none of the overlapping Notes is selected!!)
If auto correct overlapping Notes is set to disable and You do not have select your overlapping Note(s), the Notes would always auto correct shorten to XY length..(No matter if auto correct is enable or not)
-this happens after you swap the editor and or re open the item again and no note is selected...
This is a bug which make REAPER(only at the moment, hopefully) to a DAW,
which is incompatible to handle overlapping Notes..
This begin already with just two simple overlapping Notes in a row
And since newer bugs have priority for Schwa:
for this reason !,... I test it also extra with a portable 5.23
and with 5.23 this is not happen.
the first Lice is the behavior within 5.23
the second Lice the none compatible behavior within 5.28pre8
As I said for reproduce it is important to deselect the overlapping Notes first.
5.23

5.27-5.28pre xx
Greetings
EDIT
& BTW with this bug behavior above, it is of course easy possible - and a new way

to produce/get unwanted zero Note lengths..
Short Example Lice with 5.27