REGR: invalid cache after take operation with non-consolidated dataframe
a program run ok with pandas 1.0.5,  but after upgrade to 1.1.0.  it fail.
i found sometimes when I change one cell of dataframe value,  print(df) and it doesn't change.
but i use  ==, it says changed.
for example:  original  cell value is A, then i change cell value to B.   A=B
print df, it show still A
df.at(x, x) == B, it says TRUE.

-----

MarcoGorelli's edit: here's a reproducible example:

```
import pandas as pd


position = pd.DataFrame(columns=["code", "startdate"])
position = position.append([{"code": "a", "startdate": 0}])

# These two lines should not change anything.
# BUT, commenting either of them out makes this code run as intendeed
position["code"] == "A"
position[position["startdate"] == 0]

position.at[0, "code"] = "A"

print(position.at[0, "code"])
print(position)
```

output:
```
A
  code startdate
0    a         0
```

expected output:
```
A
  code startdate
0    A         0
```