Accessing values in Multi-Index dataframe with datetimes

Question

I have a problem trying to access values in a custom dataframe: My original dataframe is:

print(df)

                             Data1      Data2      Data3
IMX01  2022-08-12 22:00:00   400.00     500.00     600.00
IMX01  2022-08-15 22:00:00   400.00     500.00     600.00
IMX01  2022-08-30 22:00:00   400.00     500.00     600.00
IMX01  2022-09-12 22:00:00   400.00     500.00     600.00
IMX01  2022-09-15 22:00:00   400.00     500.00     600.00
IMX01  2022-09-30 22:00:00   400.00     500.00     600.00
RTX01  2022-08-12 22:00:00   400.00     500.00     600.00
RTX01  2022-08-15 22:00:00   400.00     500.00     600.00
RTX01  2022-08-30 22:00:00   400.00     500.00     600.00
RTX01  2022-09-12 22:00:00   400.00     500.00     600.00
RTX01  2022-09-15 22:00:00   400.00     500.00     600.00
RTX01  2022-09-30 22:00:00   400.00     500.00     600.00
...           ...              ...        ...        ...

And the custom made is filtered and grouped by the first index, and resampled by frequency (monthly) by second index (datetime).

df_custom = df[df.index.get_level_values(0).isin(["IMX01"])].sort_index(level=1).groupby(level=0).resample("M", level=1).sum()

                     Data1       Data2       Data3
IMX01  2022-08-31    1200.00     1500.00     1800.00
IMX01  2022-09-30    1200.00     1500.00     1800.00

My problem is when i tried using df_custom.loc[[("IMX01", "2022-08-31")]] it didn't work, and when i tried on the original dataframe it worked df.loc[[("IMX01", "2022-08-12 22:00:00")]]. It says: KeyError: "None of [MultiIndex([("IMX01", "2022-08-31")],\n )] are in the [index]"

I think the problem is when i resample a time series to another frequency, but i don't have any idea how to fix it. Any suggestions?