Error : The Reservation Entry Does not exist. Identification Feild and value Entry No ='9086' , Positives = yes

Same issue here, just reported by the customer today.
After quick debug, one passes throug new R2 code in codeunit 99000854 DeleteTracking functon.

IF (“Source Type” = DATABASE::“Item Ledger Entry”) AND
(“Reservation Status” = “Reservation Status”::Tracking)
THEN
IF ReservEntry1.GET(“Entry No.”,NOT Positive) THEN
ReservEntry1.DELETE;
DELETE;

So it seems at first sight, it’s possible not both entries get removed. Or, some code is missing, or some code is wrong (concerning filling with 31129999)… I hope we find out soon or being able to simulated this in a standard NAV so this can be reported to MS.