I did a second test on the same route and the outcome is the same.
Programmed the route direct in MSFS 2020 flight planner
EGNT RW07 Departure GIRL1T-07 EGPH RW06 Arrival AGPE1E-06
Result of route IFR(Low altitude airways) in the route planner from the sim
EGNT NTE05 NTS12 GIRLI AGPED HAVEN UW EGPH
In FMC A320 (Asobo):
EGNT07 NTE05 NTS12 GIRLI AGPED HAVEN DECEL D3220 D322U CI06 UW RW06
DEST EGPH06
In FMC A32NX Custom FBW:
EGNT07 NTE05 NTS12 GIRLI AGPED HAVEN DECEL USR D3220 USR D322U CI06 UW RW06 EGPH067
DEST EGPH06
The programmed route is a little bit different in the two FMC’s
Flying the route,
A320 Asobo following the route including the Sid/Star.
A32NX Custom FBW - Not following the route, making steep turns, cutting of the route.