Consultation about unit execution sequence

Hello, when I execute the following code, it seems that I can not run from the Feedstock unit (```U101```), resulting in ```Water1.F_mass``` is still obtained with the initial mass flow of stream ```Ethanol``` instead of with the flow rate of ```Ethanol``` calculating through ```Ethanol.F_mass =Feedstock.F_mass*0.098```.
If I want to run ```U101``` first, then through ```Ethanol.F_mass =Feedstock.F_mass*0.098``` to get the flow rate of stream ```Ethanol```, and then through ```Water1.F_mass = Ethanol.F_mass*7``` to get the flow rate of stream ```Water1```. Could I ask you how to solve it? Thanks for your help. Wish you a good day.
The code is as follows.
```
import biosteam as bst
from biosteam.units.decorators import cost
from biosteam import units
bst.nbtutorial()
from biorefineries import cellulosic
cs = cellulosic.Biorefinery('corn stover ethanol')
chemicals = cs.chemicals
bst.settings.set_thermo(chemicals)
bst.main_flowsheet.set_flowsheet('Glucose')

Water1 = bst.Stream(
ID='Water1',
price=0.0516,
total_flow=8992.8669,
units='kg/hr',
Water=1,
)

Glucose = bst.Stream(
ID='Glucose',
price=0.0516,
total_flow=1,
units='kg/hr',
Glucose=1,
)

Feedstock = bst.Stream(
ID='Feedstock',
price=0.0516,
total_flow=10,
units='kg/hr',
Glucose=1,
)

Ethanol = bst.Stream(
ID='Ethanol',
price=0.0516,
total_flow=10,
units='kg/hr',
Ethanol=1,
)

U101 = cellulosic.units.FeedStockHandling('U101', Feedstock)
U101.cost_items['System'].cost = 0.

@cost('Flow rate', 'Mixer', S=136260, units='kg/hr',
CE=522, cost=6000, n=0.5, BM=1)
class GlucoseMixer(bst.Mixer): pass
M201 = GlucoseMixer('M201', [Ethanol, Glucose])
@M201.add_specification(run=True)
def update_Ethanol():
Ethanol.F_mass =Feedstock.F_mass*0.098

M202 = units.Mixer('M202', [U101-0, M201-0])
P201 = units.Pump('P201', M202-0, P=1.5*101325)
H201 = units.HXutility('H201', P201-0, T=50+273.15)
P202 = units.Pump('P202', H201-0, P=2*101325)
P203 = units.Pump('P203', P202-0, P=2*101325)
@P203.add_specification(run=False)
def adjust_pump_pressure_P203():
P203._run()
After_P202 = P202-0
P203.P = After_P202.P + 0.1*101325
P204 = units.Pump('P204', P203-0, P=1.1*101325)
@P204.add_specification(run=False)
def adjust_pump_pressure_P204():
P204._run()
After_P203 = P203-0
P204.P = After_P203.P + 0.1*101325
P205 = units.Pump('P205', Water1, P=1.1*101325)
@P205.add_specification(run=True)
def update_Water():
Water1.F_mass = Ethanol.F_mass*7
M203 = units.Mixer('M203', [P205-0])
F201 = units.Flash('F201', M203-0, Q=0, P=101325)
@F201.add_specification(run=False)
def adjust_flash_pressure_F201():
F201._run()
F201_inlet = M203-0
F201.P = F201_inlet.P
M204 = units.Mixer('M204', [F201-1, P204-0])
sys = bst.main_flowsheet.create_system('sys')
sys.simulate()
sys.diagram('thorough', format='png', number=True)
Water1.F_mass
```